Class 10

Students can read Kerala SSLC Chemistry Board Model Paper March 2023 with Answers English Medium and Kerala SSLC Chemistry Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Chemistry Board Model Paper March 2023 with Answers English Medium

Time: 1½ Hours
Total Score: 40

Instructions:

• The first 15 minutes is cool-off time.
• You may use the time to read the questions and plan your answers.
• Answer only based on instructions and questions given.
• Consider score and time while answering

Section – A

Answer any four questions from 1 to 5. Each question carries 1 score.

Question 1.
The most stable outermost subshell electronic configuration of ₂₄Cr is: (1)
(3d¹⁰ 4s¹, 3d⁴ 4s², 3d⁵ 4s¹, 3d⁹ 4s¹)
Answer:
3d⁵ 4s¹

Question 2.
The volume of 1 GMM of any gas at STP is __________ (1)
Answer:
22.4 L or 22400 ml

Question 3.
Which is the product obtained at the cathode when sodium chloride solution is electrolyzed? (1)
(H₂, Cl₂, Na, O₂)
Answer:
H₂

Question 4.
Write the name of the catalyst used in the industrial production of sulphuric acid. (1)
Answer:
Vanadium Pentoxide (V₂O₅)

Question 5.
Which one of the following organic compounds undergoes an addition reaction? (1)
(CH₃ – CH₃, CH₄, CH₃Cl, CH₂ = CH₂)
Answer:
CH₂ = CH₂

Section – B

Answer any four questions from 6 to 10. Each question carries 2 scores.

Question 6.
A few drops of cone. H₂SO₄ is added to blue-colored copper sulphate crystals taken in a watch glass.
(a) Write the observation. (1)
(b) Which property of sulphuric acid is exhibited here? (1)
Answer:
(a) Blue colour of copper sulphate disappears.
(b) Dehydrating property.

Question 7.
(a) Which of the following metals is purified using the distillation method? (1)
(Tin, Lead, Zinc, Iron)
(b) Which property of the metal is used here? (1)
Answer:
(a) Zinc
(b) Low Boiling Point

Question 8.
Analyze the following chemical equation.

(a) Name of the unsaturated compound obtained as the product is __________ (1)
(b) Which type of reaction is this? (1)
(Substitution, Addition, Thermal Cracking, Polymerisation)
Answer:
(a) Propene
(b) Thermal Cracking

Question 9.
The number of molecules in a given sample of ammonia (NH₃) is 2 × 6.022 × 10²³. (1)
(a) Find the number of moles present in it.
(Atomic Mass: N = 14, H = 1)
(b) What is the mass of this sample? (1)
Answer:
(a) 2 moles
(b) 2 × 17 = 34 g (molecular mass NH₃ = 17)

Question 10.
The structure of an aromatic hydrocarbon is given.

(a) What is the name of this compound? (1)
(b) Write the molecular formula of this compound. (1)
Answer:
(a) Benzene
(b) C₆H₆

Section – C

Answer any four questions from 16 to 20. Each question carries 3 cores.

Question 11.
A gas kept in cylinder A having volume 5 L at 4 atm pressure is completely transferred to cylinder B to volume 10 L at constant temperature.
(a) What is the volume of the gas in cylinder B? (1)
(b) What will be the pressure in cylinder B? (1)
(c) Which Gas law is associated with this situation? (1)
Answer:
(a) 10 L
(b) 2 atm
V₁ = 5 L V₂ = 10 L, P₁ = 4 atm, P₂ = ?
⇒ P₁V₁ = P₂V₂
⇒ 4 × 5 = P₂ × 10
⇒ P₂ = \(\frac{4 \times 5}{10}\) = 2
(c) Boyle’s Law: At a constant temperature the volume of a definite mass of gas is inversely proportional to its pressure.
If ‘P’ is the pressure and ‘V’ the volume then
V ∝ \(\frac{1}{P}\), P × V is a constant.

Question 12.
Certain facts regarding an organic compound are given.

• It contains four carbon atoms.
• There are only single bonds between the carbon atoms.
• It is an alicyclic compound.

(a) Draw the structure of this compound. (1)
(b) Write the molecular formula of this compound. (1)
(c) Write the structure of an alkene with the same molecular formula. (1)
Answer:

(b) C₄H₈
(c) CH₃ – CH = CH – CH₃ But-2-ene or CH₂ – CH – CH₂ – CH₃ But-1-ene

Question 13.
The atomic number of an element X is 26. (Symbol is not real)
(a) Write the subshell electronic configuration of X. (1)
(b) Find the group number of X. (1)
(c) Write any one property of the elements belonging to the block in which X is included. (1)
Answer:
(a) ₂₆X = 1s², 2s² 2p⁶, 3s² 3p⁶ 3d⁶, 4s²
(b) 8
(c) All are metals.
Exhibits various oxidation states.
Produce colored compounds.
Electrons are filled in the penultimate ‘d’ subshell.
Shows similarity in groups and periods.

Question 14.
Observe the figure in which a copper plate is immersed in an AgNO₃ (Silver Nitrate) solution. (Reactivity: Cu > Ag)

(a) The reaction taking place here is a redox reaction. Why? (1)
(b) What change can be observed on the copper plate? (1)
(c) Write the equation of the oxidation reaction taking place here. (1)
Answer:
(a) Oxidation and Reduction take place simultaneously.
Cu → Cu²⁺ + 2e^– (Oxidation)
Ag¹⁺ + 1e^– → Ag (Reduction)
(b) Copperplate will be coated with silver.
(c) Cu → Cu²⁺+ 2e^–
Cu + 2Ag⁺ → Cu²⁺ + 2Ag (Redox Reaction)

Question 15.
CH₃ – COOH is the condensed formula of an organic compound.
(a) To which category does the compound belong? (1)
(alcohol, ether, ester, acid)
(b) Write the IUPAC name of this compound. (1)
(c) Write any one use of this compound. (1)
Answer:
(a) Acid
(b) Ethanoic Acid
(c) 5 – 8% of ethanoic acid is used as vinegar.
In the manufacture of rayon.
In the rubber and silk industry.

Section – D

Answer any 4 questions from 16 to 20. Each question carries 4 scores.

Question 16.
A reversible reaction at equilibrium is given.
2NO (g) + O₂ (g) \(\rightleftharpoons\) 2NO₂ (g) + Heat
(a) Write the equation of the forward reaction. (1)
(b) How do the following changes affect the rate of forward reaction?
(i) Adding more oxygen (1)
(ii) Increasing pressure (1)
(c) What is the effect of a catalyst in a reversible reaction at equilibrium? (1)
Answer:
(a) 2NO (g) + O₂ (g) → 2NO₂ + Heat
(b) (i) Rate of forward reaction increases. More product is formed.
(ii) Rate of forward reaction increases. Because due to forward reaction number of molecules decreases.
(c) Catalyst speeds up both forward and backward reactions. So equilibrium is attained earlier.

Question 17.
A and B are two organic compounds with different functional groups and having same molecular formula C₃H₈O.
(a) Write the structural formula of compound A having -OH as a functional group. (1)
(b) Write the structural formula of B. (1)
(c) Write the IUPAC name of B. (1)
(d) Write the structure of the position isomer of A. (1)
Answer:
(a) CH₃ – CH₂ – CH₂ – OH (Propan-1-ol)
(b) CH₃ – O – CH₂ – CH₃
(c) Methoxyethane

Question 18.
Aluminium is a widely used metal in daily life.
(a) Which is the ore of aluminium? (1)
(b) Which method is used for the concentration of this ore? (1)
(c) Which is the reducing agent used for the production of aluminium? (1)
(d) Why cryolite is used during the production of aluminium? (1)
Answer:
(a) Bauxite (Al₂O₃.2H₂O)
(b) Leaching (Dissolves in NaOH Alkali)
(c) Electricity
(d) Cryolite reduces the melting point of alumina.
Cryolite increases the electrical conductivity.

Question 19.
The atoms of elements A and B contain 3 shells each (symbols are not real). A belongs to group 2 and B belongs to group 16.
(a) Write the subshell electronic configuration of A. (1)
(b) What is the valecny of element B? (1)
(c) Write the chemical formula of the compound formed by the reaction of A and B? (2)
Answer:
(a) ₁₂A = 1s², 2s² 2p⁶, 3s²
(b) ₁₆B = 1s², 2s² 2p⁶, 3s² 3p⁴
Valency = 2
(c) Valency of A = 2
Valency of B = 2
Chemical Formula = AB

Question 20.
A galvanic cell is constructed using Mg and Cu as electrodes. (Reactivity: Mg > Cu)
(a) What is the energy change taking place in a galvanic cell? (1)
(b) Which is the anode of the given galvanic cell? (1)
(c) Write the equation of the chemical reaction taking place at the cathode. (1)
(d) How many galvanic cells can be constructed using the metals Mg, Zn and Cu? (1)
Answer:
(a) Chemical energy is converted to electrical energy.
(b) Mg (Magnesium)
(c) Cu²⁺ + 2e^– → Cu
(d) Three (Mg – Zn, Mg – Cu, Zn – Cu)

Students can read Kerala SSLC Chemistry Board Model Paper March 2024 with Answers English Medium and Kerala SSLC Chemistry Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Chemistry Board Model Paper March 2024 with Answers English Medium

Time: 1½ Hours
Total Score: 40

Instructions:

• The first 15 minutes is cool-off time.
• You may use the time to read the questions and plan your answers.
• Answer only based on instructions and questions given.
• Consider score and time while answering.

Section – A

Answer any four questions from 1 to 5. Each question carries 1 score.

Question 1.
Which of the following subshells is not possible? (1)
(3f, 3d, 3p, 4f)
Answer:
3f

Question 2.
Which product is obtained at the cathode when molten sodium chloride is electrolyzed? (1)
Answer:
Sodium

Question 3.
The highly concentrated aqueous solution of ammonia is known as __________ (1)
Answer:
Liquor Ammonia

Question 4.
Write the general name of the compounds having a carboxylic (-COOH) functional group. (1)
Answer:
Carboxylic Acids (RCOOH)

Question 5.
State Boyle’s Law. (1)
Answer:
At a constant temperature, the volume of a definite mass of gas is inversely proportional to its pressure.
If P is the pressure and V is the volume, then P × V is a constant.

Section – B

Answer any four questions from 6 to 10. Each question carries 2 scores.

Question 6.
Select the correct statements regarding gases from the following. (2)
(a) The real volume of gas molecules is much less when compared to the total volume of the gas.
(b) The gas molecules move in one direction only.
(c) The gas molecules are in random motion in all directions.
(d) The collisions of gas molecules are inelastic.
Answer:
(a) The real volume of gas molecules is much less when compared to the total volume of the gas.
(c) The gas molecules are in random motion in all directions.

Question 7.
A glass rod dipped in concentrated hydrochloric acid (conc. HCl) when shown over ammonia gas, thick white fumes are formed.
(a) Which is the compound formed in this experiment? (1)
(b) Write the chemical equation of the formation of this compound. (1)
Answer:
(a) Ammonium Chloride (NH₄Cl)
(b) NH₃ + HCl → NH₄Cl

Question 8.
Write the IUPAC names of the following compounds.
(a) CH₃ – CH₂Cl (1)
(b) CH₃ – CH₂ – O – CH₃ (1)
Answer:
(a) Chloro Ethane
(b) Methoxy Ethane

Question 9.
Analyse the following equation which shows the fermentation of molasses.

(a) Identify the ‘Enzyme A’. (1)
(b) Which is the product obtained when was is subjected to fractional distillation? (1)
Answer:
(a) Zymase
(b) Rectified Spirit

Question 10.
(a) Which method is used to purify zinc metal? (1)
(b) Which property of zinc is utilized here? (1)
Answer:
(a) Distillation
(b) Low boiling Point

Section – C

Answer any four questions from 11 to 15. Each question carries 3 scores.

Question 11.
The given table shows the results of an experiment on a fixed mass of gas at constant pressure.

(a) Identify the gas law represented by this table. (1)
(b) Write any one situation in daily life to which this can be related. (1)
(c) Find the volume of this gas at 100 K. (1)
Answer:
(a) Charles Law
(b) If an inflated balloon is kept in sunlight, it will burst.
(When temperature increases, the volume of the air inside the balloon increases.)
(c) According to Charles’s law, at constant pressure, \(\frac{V}{T}\) is a constant.
\(\frac{V}{T}\) = 0.03
When T = 100 K
\(\frac{V}{100K}\) = 0.03
V = 0.03 × 100 = 3 L
The volume of the gas at 100 K is 3 L.

Question 12.
A copper plate is dipped in AgNO₃ solution and kept for some time.
(a) Write any two observations concerning this reaction that takes place here. (2)
(b) Write the reason for the change that occurred in the solution. (1)
Answer:
(a) Silver is deposited on the copper plate, and the silver nitrate solution turns blue.
(b) Displacement Reaction.

Question 13.
Subshell electronic configurations of two elements are given. [Symbols are not real]
X – [Ne] 3s² 3p¹
Y – [Ne] 3s² 3p⁵
(a) Find the groups of X and Y. (1)
(b) What is the valency of Y? (1)
(c) Write the chemical formula of the compound formed by the combination of X and Y. (1)
Answer:
(a) X = 13, Y = 17
(b) 1
(c) XY₃

Question 14.
(a) Starting from ethene (CH₂ = CH₂) how will you prepare the following compounds? Write the chemical equation of each reaction.
(i) CH₃ – CH₃ (1)
(ii) CH₃ – CH₂Cl (1)
(b) Which reaction is used to get polythene from ethene? (1)
Answer:
(a) (i) CH₂ = CH₂ + H₂ → CH₃ – CH₃
(ii) CH₂ = CH₂ + HCl → CH₃ – CH₂Cl
(b) Polymerisation

Question 15.
The structural formula of an organic compound is given.
CH₃ – CH₂ – CH = CH₂
(a) This compound belongs to ___________ family. (1)
(alkane, alkene, alkyne)
(b) Write the molecular formula and IUPAC name of this compound. (1)
(c) Write the structural formula of the alicyclic compound with the same molecular formula of the above-given compound. (1)
Answer:
(a) Alkene
(b) IUPAC Name – But-1-ene
Molecular formula – C₄H₈

Section – D

Answer any 4 questions from 16 to 20. Each question carries 4 scores.

Question 16.
Analyze the given equation for the main step in the manufacture of Sulphuric acid.
2SO₂ + O₂ \(\rightleftharpoons\) 2SO₃ + Heat
(a) Write the name of the process used for the manufacture of sulphuric acid. (1)
(b) Which is the catalyst used in the manufacture of Sulphuric acid? (1)
(c) What is the effect of the following changes in the amount of SO₃ produced?
(i) More oxygen is added. (1)
(ii) Pressure is increased. (1)
Answer:
(a) Contact Process
(b) Vanadium Pentoxide (V₂O₅)
(c) (i) Forward reaction increases, and more product is formed.
(Concentration of reactant is increased, more amount is formed, rate of forward reaction increases)
(ii) Forward reaction increases, and more product is formed.
(When pressure increases, the reaction in which there is a decrease in no. of moles is favored)

Question 17.
The compound ‘A’ added to the blast furnace decomposes to give a product ‘B’ which acts as the flux in the production of Iron.
(a) Identify the compounds A and B. (2)
(b) Write the equation of slag formation in a blast furnace. (1)
(c) Which is the compound acting as the reducing agent in the blast furnace? (1)
Answer:
(a) A = Calcium Carbonate (CaCO₃)
B = Calcium Oxide (CaO)
(b) CaO + SiO₂ → CaSiO₃
(c) Carbon Monoxide

Question 18.
In a metal ‘M’ reaction with chlorine at different conditions, two compounds MCl₂ and MCl₃ are formed.
(a) Find the oxidation states of M in each of these compounds. (1)
(b) If the 3d subshell of this metal contains 6 electrons, write the complete subshell electronic configuration of this metal atom. (1)
(c) Write the subshell electronic configuration of the metal ion in MCl₂. (1)
(d) Write any one property of the elements in the block to which this metal belongs. (1)
Answer:
(a) MCl₂ – +2, MCl₃ – +3
(b) 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²
(c) 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶
(The oxidation state of that metal is +2, and 2 electrons are donated)
(d) Coloured Compounds/Different Oxidation State

Question 19.
An organic compound with -OH as the functional group has the molecular formula C₃H₈O.
(a) Write two possible structural formulae of this compound. (2)
(b) Write the structure and IUPAC name of a functional isomer of the above compounds. (2)
Answer:
(a)

and CH₃ – CH₂ – CH₂ – OH
(b) CH₃ – CH₂ – O – CH₃
IUPAC Name – Methoxy Ethane

Question 20.
Observe the following figures.

(a) In which of these beakers does a chemical reaction take place? (1)
(b) Write the chemical equation of the reaction. (1)
(c) How will you construct a galvanic cell using the materials provided in the beakers? Draw the figure of the galvanic cell and explain.
Answer:
(a) Beaker A
(b) Zn + CuSO₄ → ZnSO₄ + Cu
(c)

A galvanic cell or voltaic cell is an arrangement in which chemical energy is converted into electrical energy using a redox reaction. Arrange the apparatus as shown in the picture. Take two beakers, one containing 100 mL ZnSO₄ solution and the second containing the same amount of CuSO₄ solution with the same concentration. Dip Zn rod in ZnSO₄ solution and Cu rod in CuSO₄ solution. Connect the negative terminal of the voltmeter to the Zn rod and the positive terminal to the Cu rod. Connect the two solutions in the beakers using a salt bridge (A long filter paper that is moistened with KCl solution can be used instead of a salt bridge).

Students can read Kerala SSLC Chemistry Question Paper March 2021 with Answers English Medium and Kerala SSLC Chemistry Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Chemistry Question Paper March 2021 with Answers English Medium

Time: 1½ Hours
Total Score: 40

Instructions:

• 20 minutes is given as cool-off time.
• Use cool-off time to read the questions and plan your answers.
• Attempt the questions according to the instructions.
• Keep in mind, the score and time while answering the questions.
• The maximum score for questions from 1 to 32 will be 40.

Each question from 1 to 8 carries 1 score.

Question 1.
What is the maximum number of electrons that can be accommodated in the ‘f’ subshell? (1)
(2, 6, 10, 14)
Answer:
14

Question 2.
Identify the alkene among the given hydrocarbons. (1)
(C₂H₆, C₂H₄, C₂H₂, CH₄)
Answer:
C₂H₄

Question 3.
Metals like gold and platinum are found in their native state in the earth’s crust. Why? (1)
Answer:
Platinum and gold are less reactive metals.

Question 4.
One gram atomic mass (1 GAM) of any element contains _____________ atoms. (1)
Answer:
6.022 × 10²³

Question 5.
Select the monomer of natural rubber. (1)
[Vinyl Chloride, Ethene, Isoprene, Tetrafluoro Ethene]
Answer:
Isoprene

Question 6.
Which drying agent is used to remove moisture present in ammonia gas? (1)
Answer:
Quick Lime Calcium Oxide (CaO)

Question 7.
Which is the electrolyte used for electroplating silver on an iron bangle? (1)
Answer:
A mixture of sodium cyanide and silver cyanide or silver nitrate solution.

Question 8.
What is the energy change that takes place in a galvanic cell? (1)
Answer:
Chemical energy changes to electrical energy.

Each question from 9 to 16 carries 2 scores.

Question 9.
(a) When molten Sodium Chloride is electrolyzed, which is the gas liberated at the anode? (1)
(b) Write the chemical equation of the reaction taking place at the cathode. (1)
Answer:
(a) Chlorine
(b) Na⁺ + 1e^– → Na

Question 10.
(a) From the given subshell electronic configuration, write the correct electronic configuration of Chromium (₂₄Cr). (1)
(i) 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁴ 4s²
(ii) 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
(b) What is the reason for this selection? (1)
Answer:
(a) (ii) 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵ 4s¹
(b) Half-filled and filled ‘d’ subshells are more stable.

Question 11.
Given below are two chemical equations. (2)
(a) CH₂ = CH₂ + H₂ → A
(b) A + Cl₂ + Sunlight → B + HCl
Identify the compounds A and B.
Answer:

Question 12.
The flow chart of the industrial preparation of sulphuric acid is given. Complete it. (2)

Answer:

Question 13.
Some metals are given in the box.

(a) Which metal among these reacts vigorously with dilute HCl? (1)
(b) Which gas is liberated by this reaction? (1)
Answer:
(a) Mg
(b) Hydrogen (H₂)

Question 14.
The structure of an alkyne is given.

(a) What is the molecular formula of this compound? (1)
(b) Write the IUPAC name. (1)
Answer:
(a) C₄H₆
(b) But-1-yne

Question 15.
Two methods are used to convert concentrated ore into its oxide.
(a) Calcination
(b) Roasting
What is the difference between these?
Answer:
(a) Calcination – The ore is heated below its melting point in the absence of air.
(b) Roasting – The ore is heated below its melting point in the presence of air.

Question 16.
CH₄, C₂H₆, C₃H₈, and C₄H₁₀ are the members of a homologous series.
(a) What is the molecular formula of the 6th member of this series? (1)
(b) Write the general formula of this homologous series. (1)
Answer:
(a) C₆H₁₄
(b) C_nH_2n+2

Each question from 17 to 24 carries 3 scores.

Question 17.
The chemical formulae of two different chlorides of iron (Fe) are given below.
(i) Ferrous Chloride – FeCl₂
(ii) Ferric Chloride – FeCl₃
[Hint: Oxidation State of Chlorine Atom (Cl) = -1; Atomic Number of iron (Fe) = 26]
(a) In which compounds iron (Fe) show a +2 oxidation state? (1)
(b) Write the Subshell electronic configuration of Fe³⁺. (1)
(c) Why does iron show different oxidation states? (1)
Answer:
(a) FeCl₂
(b) Fe³⁺, 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵
(c) The difference in energy level between the outermost ‘s’ subshell and the penultimate (last but one) ‘d’ subshell is much less. So in chemical reactions not only the outermost ‘s’ subshell but also the penultimate ‘d’ subshell electrons are lost.

Question 18.
Some chemical reactions taking place in blast furnaces are given.
(i) Fe₂O₃ + 3CO → 2Fe + 3CO₂
(ii) CaCO₃ → CaO + CO₂
(iii) CaO + SiO₂ → CaSiO₃
(a) What is the chemical formula of haematite? (1)
(b) Which compound reduces haematite? (1)
(c) Identify the flux used here. (1)
Answer:
(a) Fe₂O₃
(b) CO
(c) CaO

Question 19.
The structural formula of a hydrocarbon is given.

(a) How many carbon atoms are there in the main chain? (1)
(b) What is the position number of the branch? (1)
(c) Write the IUPAC name of this compound. (1)
Answer:
(a) 5
(b) 3
(c) 3-methyl pentane

Question 20.
Some metals and their refining methods are given. Find the appropriate pair. (3)

Answer:

• Tin – Liquation
• Copper – Electrolytic Refining
• Zinc – Distillation

Question 21.
Outermost Subshell electronic configuration of two elements X and Y are given.
X = 3s²
Y = 3s²3p⁵
(Symbols are not real)
(a) What is the valency of the element X? (1)
(b) Which element shows metallic character? (1)
(c) Write the chemical formula of the compound formed by the combination of X and Y. (1)
Answer:
(a) 2
(b) X
(c) XY₂

Question 22.
The graph for the reversible reaction.
N₂ (g) + 3H₂ (g) \(\rightleftharpoons\) 2NH₃ (g) + Heat is given below.

(a) Identify and write the chemical equation associated with ‘Reaction C’ and ‘Reaction D’. (2)
(b) What is the peculiarity of the point A? (1)
Answer:
(a) Reaction C – Forward reaction
N₂ (g) + 3H₂ (g) → 2NH₃ (g) + Heat
Reaction D – Backward reaction
2NH₃ (g) + Heat → N₂ (g) + 3H₂ (g)
(b) The point ‘A’ represents the state of equilibrium. From this point the speed of forward and backward reactions are equal. But the reactions never stops.

Question 23.
The CO₂ gas kept at STP has a volume of 112 L.
[Hint: Molecular Mass – 44]
(a) Find the number of moles of CO₂. (1)
(b) Calculate the mass of 112 L CO₂. (1)
(c) How many molecules of CO₂ are present in it? (1)
Answer:
(a) 5 mol (\(\frac{112}{22.4}\) = 5)
(b) 44 × 5 = 220 g
(c) 5 × 6.022 × 10²³

Question 24.
Analyze the figure and answer the following questions.

(a) In which test tube the iron nail undergoes a colour change? (1)
(b) Write the name of the reaction taking place here. (1)
(c) Write the chemical equation of this reaction. (1)
Answer:
(a) C (Fe in CuSO₄ Solution)
(b) Displacement Reaction
(c) CuSO₄ + Fe → FeSO₄ + Cu
Cu²⁺ + Fe → Fe²⁺ + Cu

Each question from 25 to 32 carries 4 scores.

Question 25.
The subshell electronic configuration of an element is given.
1s² 2s² 2p⁶ 3s²
(a) Write the atomic number of this element. (1)
(b) To which block this element belongs? (1)
(c) Identify the period number and group number of this element. (2)
Answer:
(a) 12
(b) ‘s’ block
(c) Period – 3; Group – 2

Question 26.
The structural formulae of two organic compounds are given.
(i) CH₃ – O – CH₂ – CH₃
(ii) CH₃ – CH₂ – CH₂ – OH
(a) Write the IUPAC name of the first compound. (1)
(b) These two organic compounds are isomers. Why? (1)
(c) Which type of isomerism is exhibited by them? (1)
(d) Write the structural formula of the position isomer of the second compound. (1)
Answer:
(a) Methoxy Ethane
(b) Same molecular formula but different structural formula. Differs both in physical and chemical properties.
(c) Functional group isomerism

Question 27.
The figure of a galvanic cell is given.
[Hint: Zinc is more reactive than Copper]

(a) Identify anode and cathode. (2)
(b) What will be the direction of the flow of electrons? (1)
(c) Write the chemical equation of the reaction taking place at the anode. (1)
Answer:
(a) Anode – Zn
Cathode – Cu
(b) From Zn to Cu (From anode to cathode)
(c) Zn → Zn²⁺ + 2e^–

Question 28.
The chemical equation of the industrial preparation of ammonia is given below.
N₂ (g) + 3H₂ (g) \(\rightleftharpoons\) 2NH₃ (g) + Heat
How do the following factors influence the rate of forward reaction?
(a) Ammonia is removed from the system. (1)
(b) Temperature is increased. (1)
(c) Pressure is increased. (1)
(d) More nitrogen is added. (1)
Answer:
(a) Speed of forward reaction increases.
(b) Speed of forward reaction decreases.
(c) Speed of forward reaction increases.
(d) Speed of forward reaction increases.

Question 29.
Identify the suitable concentration method from the box and then complete the table.

Answer:
(a) Levigation (Hydraulic Washing)
(b) Magnetic Separation
(c) Froth Flotation
(d) Leaching

Question 30.
(a) What happens to the size of an air bubble rising from the bottom of an aquarium? What is the reason? (2)
(b) Which gas law is associated with this phenomenon? (1)
(c) State this law. (1)
Answer:
(a) Size increases
As the balloon rises pressure decreases and volume increases.
(b) Boyles law
(c) When the temperature remains constant the volume of a fixed mass of gas is inversely proportional to its pressure.
v ∝ \(\frac{1}{p}\) when ‘t’ is constant.

Question 31.
From the given statements, write the statements applicable to gases. (4)
(i) The energy of molecules is very high.
(ii) Attractive force between molecules is very high.
(iii) The distance between molecules is very large.
(iv) Freedom of movement of molecules is much less.
(v) As the collision of molecules is perfectly elastic, there is no loss of energy.
(vi) When compared to total volume, the real volume of molecules is much less.
Answer:
(i) The energy of molecules is very high.
(ii) The distance between the molecules is very high
(v) As the collision between the molecules is perfectly elastic there is no loss in energy.
(vi) When compared to the total volume the real volume of molecules is very less.

Question 32.
Find out the appropriate reactions and match the columns A, B and C suitably. (4)

Answer:

Students can read Kerala SSLC Chemistry Question Paper March 2022 with Answers English Medium and Kerala SSLC Chemistry Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Chemistry Question Paper March 2022 with Answers English Medium

Time: 1½ Hours
Total Score: 40

Instructions:

• There is a ‘Cool-off time’ of 15 minutes in addition to the writing time.
• Use this time to get familiar with questions and to plan your answers.
• Questions with different scores are given as distinct parts.
• Read the instructions carefully before answering the questions.
• Keep in mind, the score and time while answering the questions.
• The maximum score for questions from 1 to 24 will be 40.

Part – I

A. Answer any four questions from 1 to 6. Each carries 1 score. (4 × 1 = 4)

Question 1.
Identify the compound which contains a carbon-carbon triple bond. (1)
(C₅H₁₂, C₂H₂, C₃H₆, CH₄)
Answer:
C₂H₂

Question 2.
Which one of the following subshells has the highest energy? (1)
(1s, 3d, 4s, 3p)
Answer:
3d

Question 3.
Find the relation and fill up suitably.
(a) Tin Stone: Magnetic separation
(b) Bauxite: _____________
Answer:
Leaching

Question 4.
Which gas is produced when metals react with dilute hydrochloric acid? (1)
Answer:
Hydrogen

Question 5.
1 GMM of a substance contains _____________ several molecules. (1)
Answer:
6.022 × 10²³

Question 6.
What happens to the rates of forward and backward reaction at the equilibrium point? (1)
Answer:
The rate of forward and backward reactions becomes equal.

B. Answer all questions from 7 to 9. Each carries 1 score. (3 × 1 = 3)

Question 7.
Which metal is deposited at the cathode, when molten sodium chloride is electrolyzed? (1)
(Sodium, Hydrogen, Chlorine, Calcium)
Answer:
Sodium

Question 8.
How many electrons are donated by first-group elements generally in chemical reactions? (1)
(1, 2, 3, 4)
Answer:
1

Question 9.
In which electrode aluminium metal is produced during the electrolysis of Alumina? (1)
Answer:
Cathode

Part – II

A. Answer the following question. Carries 2 scores. (1 × 2 = 2)

Question 10.
(a) Which are the two compounds formed when Ammonium Chloride (NH₄Cl) is strongly heated? (1)
(b) Write the chemical equation for this reaction. (1)
Answer:
(a) Ammonia (NH₃) and Hydrogen chloride (HCl)
(b) NH₄Cl → NH₃ + HCl

B. Answer any one question from 11 to 12. (1 × 2 = 2)

Question 11.
Find the mass of 44.8 L of NH₃ kept at STP. (2)
(Hint: Atomic mass N = 14, H = 1)
Answer:
Molecular Mass of NH₃ = 14 + (3 × 1)
= 14 + 3
= 17
Mass of 22.4 L NH₃ = 17 g
∴ Mass of 44.8 L NH₃ = 17 × 2 = 34 g

Question 12.
(a) What is electroplating? (1)
(b) Which is the electrolyte used in the electroplating of copper on an iron bangle? (1)
Answer:
(a) Electroplating is the process of coating one metal over another using the method of electrolysis.
(b) Copper Sulphate Solution (CuSO₄)

Part – III

Answer any three questions from 13 to 16. Each carries 3 scores. (3 × 3 = 9)

Question 13.
(a) Atomic number of an element is 17. Write its subshell electronic configuration. (1)
(b) Find the group number and period number of this element in the periodic table. (2)
Answer:
(a) 1s² 2s² 2p⁶ 3s² 3p⁵
(b) Group Number = 17
Period Number = 3

Question 14.
(a) Molten iron obtained from the blast furnace contains 4% carbon and other impurities. What is this known as? (1)
(b) Which alloy steel is used for making permanent magnets? (1)
(c) Some alloy steels contain the same component. Then how do they possess different properties? (1)
Answer:
(a) Pig iron
(b) Alnico
(c) The percentage of component elements are different.

Question 15.
N₂ (g) + 3H₂ (g) \(\rightleftharpoons\) 2NH₃ (g) + Heat
How do the following changes influence the amount of the product?
(a) Temperature decreases. (1)
(b) Pressure increases. (1)
(c) Ammonia produced is removed continuously from the system. (1)
Answer:
(a) The amount of the product increases because the forward reaction is exothermic.
(b) The amount of the products increases because due to forward reaction number of molecules decreases.
(c) The amount of the product increases because the concentration of the reactants increases.

Question 16.
(X) CH₄ + 2O₂ → _______ + 2H₂O + Heat
(Y) nCF₂ = CF₂ → [-CF₂ – CF₂-] (Teflon)
(a) Complete the chemical equation X. (1)
(b) Name the reaction Y. (1)
(c) Write any one use of Teflon. (1)
Answer:
(a) CH₄ + 2O₂ → CO₂ + 2H₂O + Heat
(b) Polymerisation
(c) Used to coat the inner surface of nonstick cookware.

B. Answer the following questions carries 3 scores. (1 × 3 = 3)

Question 17.
(i) CH₃ – CH₂ – CH₂ – CH₃
(ii) CH₃ – CH₂ – CH₂ – CH₂ – OH
(iii) CH₃ – CH₂ – O – CH₂ – CH₃
(iv) CH₃ – CH₂ – CH₃
(a) Identify the isomer pair in the given compounds. (1)
(b) Name the isomerism. (1)
(c) How many isomers are possible for compound (i)? (1)
Answer:
(a) (ii) CH₃ – CH₂ – CH₂ – CH₂ – OH
(iii) CH₃ – CH₂ – O – CH₂ – CH₃
(b) Functional Group Isomerism
(c) Two

Part – IV

A. Answer any 2 questions from 18 to 20. Each carries 4 scores. (2 × 4 = 8)

Question 18.

A and B represent two gas cylinders. The gas in cylinder A is completely transferred to cylinder B, keeping the temperature constant.
(a) Compare the gas pressure in cylinder A and Cylinder B. (1)
(b) Which gas law is related to this? (1)
(c) 10 L of gas is kept in a cylinder at 2 atm pressure.
Keeping the temperature constant, the gas is completely transferred to a 20 L cylinder. What is the new pressure of the gas? (2)
Answer:
(a) Pressure in cylinder ‘B’ is greater than that of ‘A’. (Because the volume of B is less than that of A)
(b) Boyle’s law
(c) 1 atm
P₁ = 2 atm, V₁ = 10 L
P₂ = x, V₂ = 20 L
P₁V₁ = P₂V₂
⇒ 2 × 10 = x × 20
⇒ x = \(\frac{2 \times 10}{20}\) = 1

Question 19.
Haematite is converted into iron by reactions taking place in a blast furnace.
(a) Write the molecular formula of Haematite. (1)
(b) Which substance acts as the reducing agent in this process? (1)
(c) Molten iron is produced along with slag from the furnace. What is meant by slag? (1)
(d) Write the chemical equation that shows the formation of slag. (1)
Answer:
(a) Fe₂O₃
(b) Carbon Monoxide (CO)
(c) Slag is the substance formed when the flux reacts with the gangue.
Gangue + Flux → Slag
(d) CaO + SiO₂ → CaSiO₃

Question 20.

(a) How many carbon atoms are there in the longest chain of this hydrocarbon? (1)
(b) Give the name of the branch. (1)
(c) What is the position number of the branch? (1)
(d) Write the IUPAC name of the compound. (1)
Answer:
(a) 5
(b) Methyl
(c) 2
(d) 2-Methyl Pentane

B. Answer any one question from 21 to 22. (1 × 4 = 4)

Question 21.
(a) The industrial preparation of sulphuric acid is known as _____________ (1)
(b) Which is the catalyst used in this process? (1)
(c) Take some sugar in a watch glass and add a few drops of concentrated sulphuric acid to it. What is your observation? Which chemical property of sulphuric acid is shown here? (2)
Answer:
(a) Contact process
(b) Vanadium pentoxide (V₂O₅)
(c) Sugar gets charred. Carbon dioxide and water vapour evolve. Carbon is left behind.
Dehydrating nature.

Question 22.
Choose the compounds from the box and answer the following questions.
CH₃COOH, CH₃ – COO – CH₂ – CH₃, CH₃ – CH₂ – OH, C₁₂H₂₂O₁₁
(a) Which is a Carboxylic acid? (1)
(b) Which compound is an ester? (1)
(c) Identify ethanol. (1)
(d) Which substance is used in the industrial preparation of ethanol? (1)
Answer:
(a) CH₃COOH
(b) CH₃-COO-CH₂-CH₃
(c) CH₃-CH₂-OH
(d) C₁₂H₂₂O₁₁

Part – V

A. Answer anyone from 23 to 24. Each carries 5 scores. (1 × 5 = 5)

Question 23.
The atomic number of Manganese (Mn) is 25.
(a) Write the subshell electronic configuration of Mn. (1)
(b) Find the block of Mn in the periodic table. (1)
(c) Which category of elements does Mn belong? (1)
(Transition element, Halogens, Noble gases, Alkaline earth metals)
(d) What is the oxidation number of Mn in MnO₂? (1)
(Oxidation number of oxygen is -2)
(e) Write the subshell electronic configuration of Mn²⁺. (1)
Answer:
(a) ₂₅Mn = 1s² 2s² 2p⁶, 3s² 3p⁶ 3d⁵, 4s²
(b) d-block
(c) Transition Element
(d) +4
(e) Mn²⁺ = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁵

Question 24.
A picture of a galvanic cell is given below:

(a) What is the energy change taking place in a galvanic cell? (1)
(b) Identify the anode in the given cell. (1)
(c) Write the chemical equation of the reaction taking place at the anode. (1)
(d) In which electrode does oxidation take place? (1)
(e) Write the chemical equation of the redox reaction in the cell. (1)
Answer:
(a) Chemical energy changes into electrical energy.
(b) Zn rod
(c) Zn → Zn²⁺ + 2e^–
(d) Anode (Zn)
(e) Zn + Cu²⁺ → Zn²⁺ + Cu

Students can read Kerala SSLC Chemistry Question Paper March 2023 with Answers English Medium and Kerala SSLC Chemistry Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Chemistry Question Paper March 2023 with Answers English Medium

Time: 1½ Hours
Total Score: 40

Instructions:

• The first 15 minutes is cool-off time.
• You may use this time to read the questions and plan your answers.
• Answer only based on instructions and questions given.
• Consider score and time while answering.

Section – A

Answer any 4 questions from 1 to 5. Each question carries 1 score. (4 × 1 = 4)

Question 1.
The monomer of Polyvinyl Chloride is ____________ (1)
Answer:
Vinyl Chloride

Question 2.
In an atom, four electrons are present in the p sub-shell of its M shell. How is it represented? (1)
[2p⁴, 4p⁴, 3p⁴, 5p⁴]
Answer:
3p4

Question 3.
Find the relation and fill up: (1)
C_nH_2n+2: Alkane
C_nH_2n-2: ______________
Answer:
C_nH_2n-2: Alkyne

Question 4.
Phenolphthalein is pink in colour in the solution of ammonia in water. This shows that ammonia is ____________ in nature. (1)
Answer:
Basic

Question 5.
Which is the electrolyte used in electroplating copper on an iron ring? (1)
[FeSO₄, AgNO₃, ZnSO₄, CuSO₄]
Answer:
CuSO₄

Section – B

Answer any four questions from 6 to 10. Each question carries 2 scores.

Question 6.
Choose the suitable method used in each of the following processes from the bracket.
[Liquation, Leaching, Froth floatation, Distillation]
(a) Concentration of sulphide ores. (1)
(b) Refining of metals with low boiling points. (1)
Answer:
(a) Froth Floatation
(b) Distillation

Question 7.
(a) How much GMM is present in 90 g water [H₂O]? (1)
(b) Find the number of molecules present in it. (1)
[Hint: Molecular mass of water = 18]
Answer:
(a) \(\frac{90}{18}\) = 5
(b) 5 × 6.022 × 10²³

Question 8.
Ethanol is an alcohol which is extensively used for industrial purposes.
(a) What is rectified spirit? (1)
(b) How does rectified spirit differ from absolute alcohol? (1)
Answer:
(a) Rectified spirit is 95.6% pure ethanol. It is obtained by the fractional distillation of wash.
(b) Absolute alcohol is 99.5% pure ethanol. It is obtained by the fractional distillation of rectified spirit.

Question 9.
Concentrated ores are converted into their oxides by two processes.
(a) Name of the process carried out in the presence of air is ____________ (1)
(b) Which process is used in the case of carbonate ore? (1)
Answer:
(a) Roasting
(b) Calcination

Question 10.
Concentrated sulphuric acid forms nitric acid in reaction with nitrates. The chemical equation of this reaction is given below.
NaNO₃ + H₂SO₄ → NaHSO₄ + HNO₃
(a) Which sodium salt is used to get hydrochloric acid [HCl] in the same manner? (1)
(b) Write down the chemical equation of this reaction. (1)
Answer:
(a) NaCl
(b) 2NaCl + H₂SO₄ → Na₂SO₄ + 2HCl

Section – C

Answer any four questions from 11 to 15. Each question carries 3 scores.

Question 11.
Subshell electronic configurations of a few elements are given. One of them is a noble gas. [Symbols are not real]
P – 1s² 2s² 2p⁶
Q – 1s² 2s² 2p⁵
R – 1s² 2s² 2p⁶ 3s² 3p⁶ 3d² 4s²
S – 1s² 2s² 2p⁶ 3s² 3p⁶ 4s²
Answer the following questions.
(a) Which element has the highest Ionisation Energy? (1)
(b) Which element belongs to s-block? (1)
(c) Which element shows a variable oxidation state? (1)
Answer:
(a) P = 1s² 2s² 2p⁶
(b) S = 1s² 2s² 2p² 3s² 3p⁶ 4s²
(c) R = 1s² 2s² 2p⁶ 3s² 3p⁶ 3d² 4s²

Question 12.
Observe the figure.
Metals rods are dipped in salt solutions taken in three beakers.

(a) In which beaker does the displacement reaction take place? Give reason. (2)
(b) Write down the chemical equation of the oxidation reaction taking place in this beaker. (1)
[Hint: Order of reactivity Zn > Cu > Ag]
Answer:
(a) Beaker A.
Zn is more reactive than Cu. So Zn will displace Cu from the CuSO₄ solution.
(b) Zn → Zn²⁺ + 2e^–

Question 13.
Chemical equations of the reactions taking place in blast furnaces during the industrial production of iron are given below.
(i) C + O₂ → CO₂ + Heat
(ii) CO₂ + C + Heat → 2CO
(iii) Fe₂O₃ + 3CO → 2Fe + 3CO₂
(iv) CaCO₃ → CaO + CO₂
(v) CaO + SiO₂ → CaSiO₃
Answer the following questions.
(a) Which compound acts as the reducing agent? (1)
(b) What is the function of CaO in the production of iron? (1)
(c) Which is the slag formed here? (1)
Answer:
(a) CO
(b) CaO acts as a flux in the manufacture of iron.
(c) CaSiO₃

Question 14.
The structural formula of an organic compound is given.
CH₃ – CH₂ – CH = CH₂
(a) Write down the IUPAC name of this compound. (1)
(b) What is its molecular formula? (1)
(c) What is the molecular formula of the adjacent homologue coming after it? (1)
Answer:
(a) But-1-ene
(b) C₄H₈
(c) C₅H₁₀

Question 15.
Complete the table using the names of reactions given in the box. (3)

Answer:
(a) Addition Reaction
(b) Substitution Reaction
(c) Combustion

Section – D

Answer any 4 questions from 16 to 20. Each question carries 4 scores.

Question 16.
The atomic number of element X is 8.
(a) Write the subshell electronic configuration of X. (1)
(b) Find its group number and period number. (1)
(c) Write the chemical formula of the compound formed when element X reacts with Aluminium (Al). (2)
[Hint: Valency of Al = 3]
Answer:
(a) ₈X = 1s² 2s² 2p⁴
(b) Group = 16, Period = 2

Question 17.
The data given in the table shows the relation between the volume and temperature of a definite mass of gas. [Pressure is kept constant]

(a) Find ‘x’ and ‘y’. (2)
(b) Which gas law is applied here? (1)
(c) If An inflated balloon is kept in Sunlight, it will burst. Given reason. (1)
Answer:
(a) x = \(\frac{600}{300}\) = 2
y = \(\frac{800}{400}\) = 2
(b) Charle’s Law
(c) When temperature increases the volume of air inside the balloon increases. So it bursts.

Question 18.
The given diagram represents a galvanic cell.
[Hint: Order of reactivity: Mg > Cu]

(a) What is the energy change taking place in galvanic cells? (1)
(b) At which electrode does oxidation take place in galvanic cells? (1)
(c) Identify the cathode in the given cell. (1)
(d) Write down the chemical equation of the reaction taking place at the cathode in the given cell.
Answer:
(a) Chemical energy is converted into electrical energy.
(b) At anode. Here Mg rod
(c) Cu rod
(d) Cu²⁺ + 2e^– → Cu

Question 19.
The reversible reaction at equilibrium is given.
2NO (g) + O₂ (g) \(\rightleftharpoons\) 2NO₂ (g) + Heat
Answer the following:
(a) How does an increase in temperature influence the amount of product formed? (1)
(b) What change is to be made in pressure to get more product? (1)
(c) How does an increase in concentration of oxygen influence the rate of forward reaction? (1)
(d) What is the function of a catalyst in reversible reactions? (1)
Answer:
(a) When temperature increases the amount of product decreases. Because the forward reaction is exothermic.
(b) Due to forward reaction number of molecules decreases. So to get more product pressure should be increased.
(c) When the concentration of oxygen increases the amount of product increases.
(d) Catalyst speeds up both forward and backward reactions. So equilibrium is attained earlier.

Question 20.
Examine the organic compounds given below.
(i) CH₃ – CH₂ – CH₂ – CH₂ – CH₃
(ii) CH₃ – CH₂ – CH₂ – OH
(iii) CH₃ – CH₂ – CH₂ – Cl
(iv) CH₃ – CH₂ – O – CH₃

(a) Identify the isomeric pairs. (3)
(b) Which is the functional isomer pair? (2)
Answer:

Students can read Kerala SSLC Chemistry Question Paper March 2024 with Answers English Medium and Kerala SSLC Chemistry Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Chemistry Question Paper March 2024 with Answers English Medium

Time: 1½ Hours
Total Score: 40

Instructions:

• The first 15 minutes is cool-off time.
• You may use this time to read the questions and plan your answers.
• Answer only based on instructions and questions given.
• Consider score and time while answering.

Section – A

Answer any 4 questions from 1 to 5. Each question carries 1 score. (4 × 1 = 4)

Question 1.
f-block elements which belong to 7th period are known as _______________
(Transition elements, Lanthanoids, Halogens, Actinoids)
Answer:
Actinoids

Question 2.
Write the name of the byproduct obtained in the industrial production of Soap.
Answer:
Glycerol

Question 3.
The ore of a metal is lighter than the impurities. Which method is suitable for its concentration?
(Levigation, Froth Floatation, Magnetic Separation, Leaching)
Answer:
Froth Floatation

Question 4.
When ammonium chloride is heated, a gas with a basic nature is obtained. Write the name of the gas.
Answer:
Ammonia

Question 5.
Which product is obtained at the cathode when sodium chloride solution is electrolyzed?
(Na, Cl₂, O₂, H₂)
Answer:
H₂

Section – B

Answer any 4 questions from 6 to 10. Each question carries 2 scores. (4 × 2 = 8)

Question 6.
Stainless steel, Nichrome, and Alnico are alloy steels.
(a) Which alloy steel is used to produce heating coils?
(b) Identify the alloy steels having the same components among these.
Answer:
(a) Nichrome
(b) Stainless Steel and Nichrome

Question 7.
(a) The oxidation state of Mn in MnO₂ is 4. Find out the oxidation state of Mn in Mn₂O₃.
(Hint: Oxidation state of oxygen = -2)
(b) Transition elements show variable oxidation state. Why?
Answer:
(a) Mn₂O₃
2x – 6 = 0 ⇒ x = +3
(b) In the case of transition elements, along with outermost s electrons, the d electrons from the penultimate shell are also lost, as the energies of these subshells are almost equal.

Question 8.
The molecular formula of a hydrocarbon is C₄H₈.
(a) To which category does this hydrocarbon belong?
[Alkane, Alkene, Alkyne]
(b) Draw the structure of an alicyclic hydrocarbon with the same molecular formula.
Answer:
(a) Alkene

Question 9.
Analyze the picture and answer the following questions.

(a) What will be the pressure when the volume of this gas is increased to 4L at 300K?
(b) What is the gas law related to this?
Answer:
(a) P₁ = 2 atm; V₁ = 2L; V₂ = 4L
P₁V₁ = P₂V₂
P₂ = \(\frac{2 \times 2}{4}\) = 1 atm
(b) Boyle’s Law

Question 10.
Choose the right compounds from the given box to answer the following questions.
(i) CH₃ – CH₂ – OH
(ii) CH₃ – CH₂ – COOH
(iii) CH₃ – CH₂ – CO – CH₃
(iv) CH₃ – COOH
(v) CH₃ – OH
(vi) CH₃ – CH₂ – COO – CH₃
(a) Which among these is an ester?
(b) Which are the compounds required to prepare this ester?
Answer:
(a) (vi) CH₃ – CH₂ – COO – CH₃
(b) (ii) CH₃ – CH₂ – COOH
(v) CH₃ – OH

Section – C

Answer any 4 questions from 11 to 15. Each question carries 3 scores. (4 × 3 = 12)

Question 11.
Sulphuric acid is called the king of chemicals.
(a) Industrial preparation of sulphuric acid is known as _______________
(b) Which is the catalyst used in this process?
(c) A black substance is formed When concentrated sulphuric acid is added to sugar. Explain the reason for this observation.
Answer:
(a) Contact Process
(b) Vanadium Pentoxide (V₂O₅)
(c) Dehydrating nature of sulphuric acid.
Sulphuric acid absorbs hydrogen and oxygen in the form of water from sugar (C₁₂H₂₂O₁₁).

Question 12.
Silver is coated on a copper bangle by electroplating.
(a) Which metal is connected to the negative terminal of the battery in this process?
(b) Which is the electrolyte used here?
(c) Write the chemical equation of the reaction that takes place at the positive electrode.
Answer:
(a) Copper
(b) Silver Nitrate (AgNO₃) / Sodium Cyanide + Silver Cyanide Solution
(c) Ag → Ag⁺ + 1e^–

Question 13.
The structural formula of a hydrocarbon is given below.

(a) How many carbon atoms are there in the main chain?
(b) Name the branch present in the compound.
(c) Write the IUPAC name of this compound.
Answer:
(a) 6 Carbons
(b) Methyl (-CH₃) group
(c) 3-Methylhexane

Question 14.
Aluminium is the most abundant metal on the earth’s crust.
(a) Which is the ore of aluminium?
(b) Describe the different steps in the concentration of this ore.
Answer:
(a) Bauxite (Al₂O₃.2H₂O)
(b) Concentration by Leaching

Question 15.
Complete the following equations.
(a) X + Cl₂ → CH₃ – CH₂Cl + HCl
(b) CH₃ – CH = CH₂ + Cl₂ → Y
(c) CH₃ – CH₂ – CH₃ \(\rightarrow{\text { Heat }}\) CH₄ + Z
Answer:
(a) X : CH₃ – CH₃
CH₃ – CH₃ + Cl₂ → CH₃ – CH₂Cl + HCl
(b) Y : CH₃ – CHCl – CH₂Cl
CH₃ – CH = CH₂ + Cl₂ → CH₃ – CHCl – CH₂Cl
(c) Z : CH₂ = CH₂
CH₃ – CH₂ – CH₃ \(\rightarrow{\text { Heat }}\) CH₄ + CH₂ = CH₂

Section – D

Answer any 4 questions from 16 to 20. Each question carries 4 scores: (4 × 4 = 16)

Question 16.
The subshell electronic configuration of an element is given:
1s² 2s² 2p⁶ 3s² 3p⁶ 3d⁶ 4s²
(a) What is the atomic number of this element?
(b) Which subshell among these has the highest energy?
(c) Find out the period number and group number of this element.
Answer:
(a) 26
(b) 3d has the highest energy
(c) Period Number = 4
Group Number = 2 + 6 = 8

Question 17.
The structural formula of an organic compound is given:
CH₃ – CH₂ – O – CH₃
(a) The compounds having – O – R as the functional group are called _______________
(b) Write the molecular formula of this compound.
(c) Write the IUPAC name of this compound.
(d) Write the structural formula of the functional isomer of this compound.
Answer:
(a) Ether
(b) C₃H₈O
(c) Methoxyethane
(d) CH₃ – CH₂ – CH₂ – OH
or

Question 18.
(a) What is the volume of 1 mol ammonia gas (NH₃) at STP?
(b) Find the volume of 68 g ammonia gas at STP.
[Hint: Molecular Mass of NH₃ = 17]
(c) Find the number of molecules present in 68 g ammonia gas.
Answer:
(a) 22.4 L
(b) No. of moles \(=\frac{\text { Given mass }}{\text { GMM }}\)
= \(\frac{68}{17}\)
= 4 mole
Volume = Mole × 22.4
= 4 × 22.4
= 89.6 E
(c) No. of molecules = Mole × N_A
= 4N_A (4 × 6.022 × 10²³)

Question 19.
2NO (g) + O₂ (g) = 2NO₂ (g) + Heat
(a) When does a reversible reaction attain equilibrium?
(b) How do the following changes influence the amount of the product?
(i) Increase in temperature
(ii) Increase in pressure
(iii) NO₂ is removed from the system.
Answer:
(a) The system attains equilibrium when the rate of forward reaction becomes equal to the rate of backward reaction.
(b) (i) The amount of product decreases.
(ii) the amount of product increases.
(iii) amount of product increases.

Question 20.
The order of reactivity of some elements is given. Analyze it and answer the following questions.
Mg > Zn > Fe > Cu > Ag
(a) Name any one metal that cannot displace hydrogen from dilute hydrochloric acid.
(b) Which are the metals that can displace Fe from the FeSO₄ solution?
(c) A galvanic cell is constructed using Zn and Fe as electrodes.
(i) Which is the anode of this cell?
(ii) Write the equation of the chemical reaction taking place at the cathode.
Answer:
(a) Copper (Cu) or Silver (Ag)
(b) Mg and Zn
(c) (i) Zn
(ii) Fe²⁺ + 2e^– → Fe

Students can read Kerala SSLC Physics Board Model Paper March 2022 with Answers English Medium and Kerala SSLC Physics Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Physics Board Model Paper March 2022 with Answers English Medium

Time: 1½ Hours
Score: 40

Instructions:

• There is a ‘Cool-off time’ of 15 minutes in addition to the writing time. Use this time to get familiar with questions and to plan your answer.
• Questions with different scores are given as distinct parts.
• Read the instructions carefully before answering the questions.
• Keep in mind, the score and time while answering the questions.
• The maximum score for questions from 1 to 24 will be 40.

Part – I

A. Answer any four questions from 1 to 6. Each carries 1 score. (4 × 1 = 4)

Question 1.
Name the arrangement in a DC motor to sustain the rotation of the armature in one direction. (1)
Answer:
Split Ring Commutator

Question 2.
In the figure, a beam of light is incident on a surface and its reflection is depicted.

If the angle between them is 60° what will be the angle of incidence? (1)
Answer:
30°

Question 3.
If the intensity of the electric current in a circuit is doubled the heat energy developed in this circuit increases _________ times. (1)
(2, \(\frac{1}{2}\), 4, \(\frac{1}{4}\))
Answer:
4

Question 4.
Which among the following is the graphical representation of the output emf in a DC generator? (1)

Answer:

Question 5.
Which of the mirrors forms an image larger than the object? (1)
(Plane Mirror, Concave Mirror, Convex Mirror)
Answer:
Concave Mirror

Question 6.
In which condition do all the component colors of white light undergo the same scattering? (1)
Answer:
If the size of the particles is greater than the wavelength of light, the scattering is the same for all colours.

B. Answer all questions from 7 to 9. Each carries 1 score. (3 × 1 = 3)

Question 7.
Which of the following light sources does not contain mercury in it? (1)
(Fluorescent Lamp, LED, CFL)
Answer:
LED

Question 8.
Which rule gives the direction of current produced in a conductor when it moves perpendicular to a magnetic field? (1)
Answer:
Fleming’s Right Hand Rule

Question 9.
If two plane mirrors are placed at an angle of 60° between them what will be the number of images formed by them? (1)
Answer:
5

Part – II

A. Answer the following question carries a 2 score. (1 × 2 = 2)

Question 10.
Write any two characteristic properties of the material used as a heating coil in heating devices. (2)
Answer:
High Resistance, High Melting Point

B. Answer any one question from 11 to 12. (1 × 2 = 2)

Question 11.
How many units of energy will be consumed by a 100 W bulb in 30 days, if it works 10 hours every day? (2)
Answer:
Electrical Energy = \(\frac{\text { Power } \times \text { time in hour }}{1000}\)
= \(\frac{100 \times 10 \times 30}{1000}\)
= 30 kWh
= 30 unit

Question 12.
Explain how light energy is produced in discharge lamps. (2)
Answer:
When high potential difference is applied, the gas molecules get excited. Excited atoms come back to their orginal states for attaining stability. During this process, the energy stored in them will be radiated as light.

Part – III

A. Answer any three questions from 13 to 16. Each carries 3 scores. (3 × 3 = 9)

Question 13.
A real image is formed at a distance of 20 cm from a concave mirror when an object is placed at a distance of 30 cm from the mirror.
(a) Calculate the focal length of the mirror using the New Cartesian sign convention. (2)
(b) What will be the magnification of the image? (1)
Answer:

Question 14.
Solenoids are used to make electromagnets.
(a) If the direction of the DC through the solenoid at the end facing us is clockwise, which magnetic pole is developed at this end? (1)
(b) Suggest two methods to increase the magnetic field strength of a solenoid. (2)
Answer:
(a) South Pole
(b) Increase the number of turns.
Increase the intensity of the electric current.

Question 15.
Observe the figure of the microphone.

(a) Write the names of Part A and B of the moving coil microphone. (1)
A = ____________
B = ____________
(b) How do electrical signals by the sound are generated in the microphone? (2)
Answer:
(a) A = Diaphragm
B = Voice Coil
(b) The diaphragm vibrates when sound waves fall on it. Voice coil connected with the diaphragm. Vibrates in a strong magnetic field. As a result, electrical signals corresponding to the sound waves are generated in the voice coil.

Question 16.
Observe the given diagram.

(a) When a light ray enters the air from water the light ray ___________ (1)
[moves towards the normal/moves away from the normal]
(b) Name the phenomenon that caused the deviation of the light rays when entered into air from the water. (1)
(c) What happens to the speed of light when it enters from water to air? (1)
[Increase, Decrease, No change]
Answer:
(a) Bends away from the normal
(b) Refraction
(c) Increases

B. Answer the following question carries a 3 score. (1 × 3 = 3)

Question 17.
Observe the given figure.

(a) Bulb in which circuit will glow with low intensity? (1)
(b) Explain the reason for the decrease in the intensity of light in this bulb. (2)
Answer:
(a) b
(b) While AC passes through the coil, magnetic flux changes. So a back emf is induced in the same coil. Thus due to self-induction, effective, voltage decreases.

Part – IV

A. Answer any 2 questions from 18 to 20. Each carries 4 scores. (2 × 4 = 8)

Question 18.
Coal is divided into four categories, peat and lignite are two of them.
(a) Which are the other two? (1)
(b) On what basis does coal is categorized like this? (1)
(c) Which are the products obtained when coal is distilled in the absence of air? (2)
Answer:
(a) Anthracite, Bituminous Coal
(b) Based on Carbon Content
(c) Coke, Coal Tar, Coal Gas, Ammonia

Question 19.
Observe the position of the object OB placed in front of a convex lens.

(a) Draw the ray diagram of image formation and find the position of the image. (2)
(b) Write any two features of the image formed. (1)
(c) Calculate the power of a convex lens with a focal length of 50 cm. (1)
Answer:

Question 20.
Observe the figure in which image formation in an eye is given.

(a) Name the defect of this eye. (1)
(b) What is the reason for this defect? (2)
(c) Suggest a remedy for this. (1)
Answer:
(a) Near-sightedness or myopia
(b) Excessive curvature of the eye lens.
Elongation of eyeball.
(c) Use a concave lens of suitable focal length.

B. Answer any one question from 21 to 22 (1 × 4 = 4)

Question 21.
(a) Which material is used as filament in incandescent lamps? (1)
(b) What are the characteristic properties of the material used as a filament? (2)
(c) Why these lamps are filled with Nitrogen? (1)
Answer:
(a) Tungsten
(b) High Resistance.
High Melting Point.
Can be drawn into thin wires/with high ductility.
Can emit white light.
(c) To decrease vaporization.

Question 22.
(a) When a beam of light entered into glass from the air it was found the angle of incidence was ‘i’ and the angle of refraction as ‘r’ state Snells’ law which relates these angles. (2)
(b) Calculate the refractive index when the light enters into glass from the air, if the velocity of light in air is 3 × 108 m/s and the velocity of light in glass is 2 × 10⁸ m/s. (2)
Answer:
(a) The ratio of the sine of the angle of incidence to the sine of the angle of refraction \(\left(\frac{\sin i}{\sin r}\right)\) will always be a constant.
(b) Refractive index \(=\frac{\text { speed of light in air }}{\text { speed of high in the medium }}\)
= \(\frac{c}{v}\)
= \(\frac{3 \times 10^8}{2 \times 10^8}\)
= 1.5

Part – V

A. Answer anyone from 23 to 24. Each carries 5 scores. (1 × 5 = 5)

Question 23.
The following figure represents a transformer with no power loss.

(a) What type of transformer is shown in the figure? (1)
(b) Name the principle based on which this trans-former works. (1)
(c) If the output from the secondary of this transformer is 50 V, 10 W electric power.
(i) What will be the input voltage? (2)
(ii) What is the current in the primary? (1)
Answer:
(a) Step Down Transformer
(b) Mutual Induction
(c) (i) 200 V
(ii) P = I × V
∴ I = \(\frac{P}{V}\)
= \(\frac{10}{200}\)
= 0.05 A

Question 24.
Usually, we connect resistors in series and parallel.
(a) In which type of connection does the resultant resistance of the circuit decreases? (1)
(b) Two resistors of 100 Ω are connected in series with a 250 V supply. Calculate the heat energy produced when current flows through it for 2 seconds. (2)
(c) State whether the quantity of heat produced increases or decreases, if these resistors are connected in parallel in the same circuit with a 250 V supply. Justify your answer. (2)
Answer:
(a) Series Connection
(b) R = R₁ + R₂
= 100 + 100
= 200 Ω
V = 250 V, t = 2s
H = \(\frac{V^2 t}{R}\)
= \(\frac{250 \times 250 \times 2}{200}\)
= 625 J
(c) Increases, effective resistance decreases in parallel connection, so current increases, heat increases. (H = I²Rt)

Students can read Kerala SSLC Physics Board Model Paper March 2023 with Answers English Medium and Kerala SSLC Physics Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Physics Board Model Paper March 2023 with Answers English Medium

Time: 1½ Hours
Score: 40

Instructions:

• The first 15 minutes is cool-off time.
• You may use the time to read the questions and plan your answers.
• Answer only based on instructions and questions given.

Section – A

Answer any four questions. Each question carries 1 score.

Question 1.
Identify the relation from the first pair and complete the second pair suitably. (1)
Moving Coil Microphone: Sound Energy → Electrical Energy.
Power Generator: __________ → __________
Answer:
Power Generator: Mechanical Energy → Electrical Energy

Question 2.
Which of the following is related to green energy sources? (1)
(Atomic Reactor, Diesel Engine, Wind Mill, Thermal Power Station)
Answer:
Wind Mill

Question 3.
Which of the given statements is true? (1)
(a) Long-sightedness can be rectified by using the concave lens of suitable power.
(b) The near point of a person with Long-sightedness is more than 25 cm.
(c) The far point of a person with Near-sightedness is at infinity.
(d) Short-sightedness can be rectified by using a convex lens of suitable power.
Answer:
(b) The near point of a person with Long-sightedness is more than 25 cm.

Question 4.
Identify the mirror which always forms a virtual and diminished image. (1)
(Plane Mirror, Convex Mirror, Concave Mirror)
Answer:
Convex Mirror

Question 5.
According to New Cartesian Sign Conventions, a sign of the focal length of a concave lens is __________ (1)
Answer:
Negative

Section – B

Answer any four questions. Each question carries 2 scores.

Question 6.
Calculate the power of a heating appliance having 230 Ω resistance when 2 A current flows through it. (2)
Answer:
R = 230 Ω, I = 2 A
p = I²R
= 2² × 230
= 4 × 230
= 920 W

Question 7.
Observe the figure.

(a) Which part of this device converts electric energy into sound energy? (1)
(b) What is the working principle of this device? (1)
Answer:
(a) Voice Coil and Diaphragm.
(Voice coil converts electrical signal into mechanical energy, diaphragm converts it into sound energy)
(b) Motor Principle

Question 8.
A ray of light traveling from glass to air graces through the surface of the glass is shown in the figure.

(a) Name the angle of incidence (i) in the figure. (1)
(b) Can we reflect the incident ray into the glass? Justify your answer. (1)
Answer:
(a) Critical Angle
(b) Yes. Increase the angle of incidence, then the ray will undergo total internal reflection, i.e., the ray will be reflected to the same medium.

Question 9.
The angle between the reflecting surfaces of two plane mirrors is 30°.
(a) How many images are formed when an object is placed in between them? (1)
(b) Write any two characteristics of the image formed by a plane mirror. (1)
Answer:
(a) n = \(\frac{360}{\theta}\) – 1
= \(\frac{360}{30}\) – 1
= 12 – 1
= 11 images
(b) Virtual, Erect

Question 10.
The primary and secondary currents of a transformer are 2 A and 4 A respectively. The output voltage of this transformer is 100 V.
(a) Identify the transformer. (1)
(b) Calculate the primary voltage of the transformer. (1)
Answer:
(a) Step Down Transformer
(b) V_p × I_p = V_s × I_s
∴ V_p = \(\frac{\mathrm{V}_{\mathrm{S}} \times \mathrm{I}_{\mathrm{s}}}{\mathrm{I}_{\mathrm{P}}}\)
= \(\frac{100 \times 4}{2}\)
= 200 V

Section – C

Answer any four questions. Each question carries 3 scores.

Question 11.
The figure shows the dispersion of a ray of light passing through a water drop in the atmosphere.

(a) What are the phenomena of light that the ray undergoes inside the drop? (1)
(b) Identify and write down the colours P and Q. (1)
(c) What are the colours seen in the inner and outer edges of the primary rainbow? (1)
Answer:
(a) Dispersion, Internal Reflection and Refraction
(b) P – Violet, Q – Red
(c) Inner Edge – Violet and Outer Edge – Red

Question 12.
Fuse, MCB, ELCB, and RCCB are used to ensure safety in household electric circuits.
(a) What is the difference between the functioning of Fuse and MCB? (1)
(b) What is the advantage of MCB over Fuse? (1)
(c) What is the function of ELCB and RCCB in electric circuits? (1)
Answer:
(a) Fuse – In fuse, fuse wire melts due to excess current. It works based on the heating effect of electric current.
MCB – It has an internal switch that gets tripped when there is excess current. It works based on the magnetic effect and the heating effect of electrical energy.

(b) In MCB, after solving the problem, the switch can be turned on. But in the fuse, the melted fuse wire is to be replaced by another suitable wire. Moreover, MCB is more sensitive than fuse. MCB is simple to resume the supply.

(c) ELCB helps to break the circuit automatically when there is leakage of current due to insulation failure or short circuit, It protects the user from electric shock. RCCB also breaks the circuit, so that there is no harm due to electric shock. RCCB ensures more safety.

Question 13.
The conductor AB which is connected to a battery is placed between the poles of a U-shaped magnet perpendicular to the magnetic field lines.

(a) In which direction the conductor deflects when the circuit is switched on? (1)
(b) Which law helps to detect the direction of the conductor? State the law. (2)
Answer:
(a) P
(b) Fleming’s Left Hand Rule: Stretch the forefinger, middle finger, and thumb of the left hand in mutually perpendicular directions. The fore finger indicates the direction of the magnetic field, the middle finger indicates the direction of the current, then the thumb indicates the direction of motion of the conductor.

Question 14.
A branch circuit of a household electric circuit is shown in the figure.

(a) Find out any two mistakes in the circuit. (1)
(b) Draw the circuit correctly. (2)
Answer:
(a) (1) In the figure, the fuse is wrongly connected to the neutral wire. The fuse should be connected to the phase line.
(2) The large pin of the pin plug is wrongly connected to P in the figure. It should be connected to E, earth.
(b)

Question 15.
A lighted candle is placed 20 cm away in front of a spherical mirror. A real and inverted image is formed at the same distance.
(a) Identify the mirror used for the experiment. (1)
(b) What is the focal length of the mirror? (1)
(c) Calculate the magnification. (1)
Answer:
(a) Concave Mirror
(b) 10 cm
(c) -1

Section – D

Answer any four questions. Each question carries 4 scores.

Question 16.
Observe the electric circuit in which 40 Ω and 60 Ω resistors are connected in parallel.

(a) Calculate the effective resistance. (1)
(b) What is the current flowing through a 40 Ω resistor? (1)
(c) What is the heat generated in a 60 Ω resistor if current flows through it in 2 minutes? (2)
Answer:

Question 17.
The cooking gas that we get in cylinders is LPG.
(a) What indicates the label ‘B 23′ in the LPG cylinder? (1)
(b) Which is the main constituent of LPG? (1)
(c) Which substance is added in LPG to detect the leakage of the cylinder? (1)
(d) What precautions are to be taken to avoid accidents due to LPG leakage? (1)
Answer:
(a) It means that the cylinder expires in June 2023.
(b) Butane
(c) 1. Turn off the main switch.
2. Close the regulator
3. Isolate the cylinder into an open space and cover it with a wet cloth.

Question 18.
The figure shows the image formation in the eye of a person. Observe the figure and answer the following.

(a) Where is the image formed? (1)
(in front of the retina, at the retina, behind the retina)
(b) Identify the defect of the eye shown in the figure. (1)
(c) What are the reasons for this defect? (1)
(d) How can we rectify this defect? (1)
Answer:
(a) Behind the retina
(b) Long-sightedness or hypermetropia
(c) Eyeball is shorter than normal, decreased power of the eye lens.
(d) Use a convex lens of suitable power.

Question 19.
A ray diagram related to image formation is given below.

(a) Copy and complete the diagram to show the image formation. (2)
(b) Write the characteristics of the image formed. (1)
(c) Magnification of the image is _________ (1)
(Greater than 1, 1, Less than 1)
Answer:
(a)

(b) Inverted, Real, Enlarged.
(c) Greater than 1.

Question 20.
Nowadays natural disasters occur frequently in Kerala. If the walls of our house are wet due to flooding the chance of getting electric shock is more.
(a) What are the precautions to be taken to avoid electric shock during these situations? (1)
(b) What is to be done at first when a person is getting electric shock? (1)
(c) What are the First aids to be given in the case of electric shock? (2)
Answer:
(a) 1. Do not operate electric switches with wet hands.
2. Wear rubber slippers while handling electric appliances.
(b) Disconnect the source of electricity.
(c) Increase the body temperature by massaging. Give artificial respiration, and shift to the hospital immediately.

Students can read Kerala SSLC Physics Board Model Paper March 2024 with Answers English Medium and Kerala SSLC Physics Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Physics Board Model Paper March 2024 with Answers English Medium

Time: 1½ Hours
Total Score: 40

Instructions:

• The first 15 minutes is cool-off time.
• You may use the time to read the questions and plan your answers.
• Answer only based on instructions and questions given.
• Consider score and time while answering.

Section – A

Answer any four questions. Each question carries 1 score. (4 × 1 = 4)

Question 1.
Find the relation in the first pair and complete the second. (1)
(i) Electric iron: Heating effect
(ii) Electric motor: ______________
Answer:
(i) Electric iron: Heating effect
(ii) Electric motor: Magnetic effect

Question 2.
Which of the following is not a part of a moving coil loudspeaker? (1)
(Voice Coil, Diaphragm, Permanent Magnet, Slip Rings)
Answer:
Slip Rings

Question 3.
Find the angle of incidence in the following figure. (1)

Answer:
50°
The angle between the incident ray and the reflected ray is 100°.
Since ∠i = ∠r
∠i = \(\frac{100}{2}\) = 50°

Question 4.
What is the energy conversion taking place in a windmill? (1)
Answer:
Wind Energy → Mechanical Energy → Electrical Energy

Question 5.
How long does an electrical device of power 500 W work to consume 1 unit of electrical energy? (1)
Answer:
Energy in kilowatt hour = \(\frac{\text { Power in watt } \times \text { time in hour }}{1000}\)
Energy = 1 unit
Power = 500 W
Time = \(\frac{\text { Energy } \times 1000}{\text { Power }}=\frac{1 \times 1000}{500}\)
Time = 2 hours

Section – B

Answer any four questions. Each question carries 2 scores. (4 × 2 = 8)

Question 6.
Write any four methods to minimize the energy crisis. (2)
Answer:

• Use energy judiciously.
• Use renewable sources of energy like solar energy maximum as possible.
• Construct houses to get sufficient sunlight and air circulation.
• Use machines haying high efficiency.

Question 7.
A soldering iron of resistance 1250 Ω works with a supply of 200 V.
(a) Find the power of the soldering iron. (1)
(b) Calculate the amount of heat energy produced in 10s. (1)
Answer:
(a) Power, P = V²/R
= 200²/1250
= 32 W
(b) Heat energy, H = Pt
= 32 × 10
= 320 J

Question 8.
Classify the energy produced from the following sources as green energy and brown energy. (2)
(Solar Power Plant, Atomic Reactor, Diesel Engine, Hydroelectric Power Station)
Answer:

Green Energy	Brown Energy
Solar Power Plant	Atomic Reactor
Hydroelectric Power Station	Diesel Engine

Question 9.
Analyze the following figure and answer the questions.

(a) Which medium has more optical density? (1)
(b) Calculate the speed of light in water if the refractive index of water is 1.33. (Speed of light in air = 3 × 10⁸ m/s) (1)
Answer:
(a) Water
(b) Speed of light in water = \(\frac{\text { speed of light in air }}{\text { refractive index of water }}=\frac{3 \times 10^8}{1.33}\) = 2.25 × 10⁸ m/s

Question 10.
Analyze the following statements and correct the mistakes if any:
(a) According to the new Cartesian sign convention the distance of the object from a mirror is always positive. (1)
(b) Fleming’s left-hand rule helps to identify the direction of the magnetic field around a current-carrying conductor. (1)
Answer:
(a) False.
According to the New Cartesian Sign convention, the distance of the object from a mirror is always negative.
(b) False.
The Right-hand thumb rule is used to identify the direction of the magnetic field around a current-carrying conductor.
OR
Fleming’s left-hand rule is used to identify the direction of magnetic force on a current-carrying conductor placed in a magnetic field.

Section – C

Answer any four questions. Each question carries 3 scores. (4 × 3 = 12)

Question 11.
Analyze the following circuits:

(a) In which circuit the bulbs are connected in parallel? (1)
(b) The bulbs in which the circuit glows brighter when all the switches are put on? (1)
(c) Justify your answer. (1)
Answer:
(a) Circuit A
(b) Circuit A
(c) In a parallel connection, the source voltage is fully available at both lamps whereas in a series connection, the applied voltage is split between the lamps.

Question 12.
Match the following.

A	B	C
Plane Mirror	Rear View Mirror	Magnification is more
Convex Mirror	Shaving Mirror	The size of the image is the same as that of the object.
Concave Mirror	Periscope	Larger field of view

Answer:

A	B	C
Plane Mirror	Periscope	The size of the image is the same as that of the size of the object.
Convex Mirror	Rearview Mirror	Larger field of view
Concave Mirror	Shaving Mirror	Magnification is more

Question 13.
A ray diagram of the image formation in the human eye is depicted. Analyze the figure and answer the questions.

(a) Which figure indicates an eye with short-sightedness? (1)
(b) What are the reasons for this defect? (1)
(c) How is it rectified? (1)
Answer:
(a) Figure B
(b) Reasons for the defect:

• The eyeball is larger than the normal size.
• The focal length of the eye lens is shorter than the required focal length.

(c) By using the concave lens of suitable power.

Question 14.
Two magnets and a current-carrying conductor AB are placed on the top of a table as shown in the figure.

(a) In which direction should the current flow through the conductor to move it in a direction upwards from the table? (1)
(b) Which rule helps you to find the answer? (1)
(c) Write any two devices that work on this principle. (1)
Answer:
(a) From A to B.
(b) Fleming’s left-hand rule.
(c) Electric motor, moving coil loudspeaker.

Question 15.
Analyze the following figure and answer the questions.

(a) Find the angle of refraction. (1)
(b) Write any angle of incidence that produces total internal reflection. (1)
(c) Write any two practical applications of total internal reflection. (1)
Answer:
(a) 90°
(b) 50° (Any angle larger than 42°)
(c) Optic fiber, Endoscope.

Section – D

Answer any four questions. Each question carries 4 scores. (4 × 4 = 16)

Question 16.
An electric circuit consisting of two incandescent lamps is depicted below. Analyze the circuit and answer the questions.

(a) Which material is used as filament in incandescent lamps? (1)
(b) Calculate the current through the circuit when S₁ and S₂ are put on. (2)
(c) What happens to the circuit when all the switches are put on? (1)
Answer:
(a) Tungsten
(b) When S₁ and S₂ are ON, the circuit becomes short-circuited, and the fuse wire will be burned out. (Question is wrong)
If S₂ and S₃ are on the current in the circuit
I = \(\frac{100}{200}+\frac{100}{200}\) = 1 A
(c) A short circuit will happen, and the fuse wire will be burned out.

Question 17.
A transformer without power loss works at an input of 250 V. A current of 1 A flows through the secondary coil when an electrical device of power 50 W is connected to the secondary.
(a) Which type of transformer is used here? (1)
(b) What is the working principle of a transformer? ( 1)
(c) Calculate the current through the primary. (1)
Answer:
(a) P_s = V_s × I_s
50 = V_s × 1
V_s = 50 V
Since V_s is less than V_p, it is a step-down transformer.
(b) Mutual Induction
(c) \(\frac{V_s}{V_p}=\frac{I_p}{I_s}\)
V_p = 250 V
I_s = 1 A
I_p = \(\frac{\mathrm{V}_{\mathrm{s}} \times \mathrm{I}_{\mathrm{s}}}{\mathrm{~V}_{\mathrm{p}}}=\frac{50 \times 1}{250}\) = 0.2 A

Question 18.
Analyze the following schematic diagram and answer the questions.

(a) Name the device. (1)
(b) Which are the main parts of this device? (2)
(c) Illustrate the graphic representation of the output when the field magnet is rotated by keeping the armature stationary. (1)
Answer:
(a) DC Generator.
(b) Armature, field magnet, split ring commutator, and brushes.
(c)

Question 19.
The following diagram represents the passage of light from an object through a lens MN.

(a) Which type of lens is MN? (1)
(b) Copy and redraw the diagram to get the image of the object. (2)
(c) Write any two characteristics of this image. (1)
Answer:
(a) Concave Lens
(b)

(c) Erect, Virtual, Smaller than the object.

Question 20.
Analyze the following figure and answer the questions.

(a) Which are the colours obtained on the screen? (1)
(b) Which among these has the longest wavelength? (1)
(c) Name the process by which light splits up into its constituent colours. (1)
(d) What difference is observed when red laser light is used instead of sunlight? (1)
Answer:
(a) Violet, Indigo, Blue, Green, Yellow, Orange, and Red. [All visible colours]
(b) Red
(c) Dispersion
(d) There is no dispersion. That is only red colour is obtained on the screen as it is composed of only one colour.

Students can read Kerala SSLC Physics Question Paper March 2021 with Answers English Medium and Kerala SSLC Physics Previous Year Question Papers with Answers helps you to score more marks in your examinations.

Kerala Syllabus Class 10 Physics Question Paper March 2021 with Answers English Medium

Time: 1½ hrs
Score: 40

Instructions:

• 20 minutes is given as cool-off time.
• Use cool-off time to read the questions and plan your answers.
• Attempt the questions according to the instructions.
• Keep in mind, the score and time while answering the questions.
• The maximum score for questions from 1 to 34 will be 40.

Each question from 1 to 8 carries 1 score.

Question 1.
Choose the least scattered colour in sunlight from the following. (1)
[Violet, Green, Blue, Red]
Answer:
Red

Question 2.
The non-rotating part in a dc motor is _________ (1)
[Armature, Split ring, Graphite Brush]
Answer:
Graphite Brush

Question 3.
Select the odd one from the group. (1)
[Reflection, Dispersion, Refraction, Persistence of Vision]
Answer:
Persistence of Vision

Question 4.
If the object distance and image distance in a concave mirror is 40 cm, what is its focal length? (1)
Answer:

Question 5.
Observe the relations between terms in the first pair and complete the second pair. (1)
CNG: Compressed Natural Gas
LNG: ________________
Answer:
LNG: Liquified Natural Gas

Question 6.
Pick out the one that is not a source of Green Energy. (1)
[Solar Cell, Wind Mill, Biogas, LPG]
Answer:
LPG

Question 7.
Which phenomenon of light is utilized in optical fiber technology? (1)
[Refraction, Total Internal Reflection, Dispersion, Scattering]
Answer:
Total Internal Reflection

Question 8.
The image formed by a convex lens is inverted and diminished. Then the object must be placed: (1)
[At 2F, Beyond 2F, Between F and 2F, At F]
Answer:
Beyond 2F

Each question from 9 to 20 carries 2 scores.

Question 9.
Write the energy change taking place in the given devices.
(a) Incandescent Lamp (1)
(b) Electric Mixie (1)
Answer:
(a) Incandescent lamp: Electrical energy → light energy
(b) Electric mixie: Electrical energy → Mechanical energy

Question 10.
(a) Name the part of a heating equipment in which the electric energy is converted into heat energy. (1)
(b) Name the substance used to make this part. (1)
Answer:
(a) Heating Coil
(b) Nichrome

Question 11.
Explain the difference between short circuits and overloading. (2)
Answer:
Short Circuit:
If the positive and negative terminals of a battery or the two wires from the mains come into contact without the presence of resistance in between, they are said to be in a short circuit.

Overloading:
A circuit is said to be overloaded if the total power of all the appliances connected to it is more than what the circuit can withstand.

Question 12.
Write any two methods to increase the magnetic strength of a current-carrying solenoid. (2)
Answer:

• By increasing the number of turns of the coil.
• By increasing the intensity of the electric current.
• By increasing the area of the cross-section of the core.

Question 13.
Observe the figure of a moving coil loudspeaker.

(a) Name the parts labeled as A and B. (1)
(b) Write the function of the diaphragm in this device. (1)
Answer:
(a) A – Voice Coil
B – Field Magnet
(b) The voice coil, which is placed in the magnetic field, moves to and fro rapidly when electrical pulses pass through it. These movements make the diaphragm vibrate thereby reproducing sound. The diaphragm helps to convert electrical energy into mechanical energy or sound energy.

Question 14.
Write any two relevant first aids to be given in the case of electric shock. (2)
Answer:
After removing the electric connection,

• Raise the temperature of the body by massaging.
• Give artificial respiration.

Question 15.
Explain the following.
(a) Electromagnetic Induction (1)
(b) Induced emf (1)
Answer:
Whenever there is a change in magnetic flux linked with a coil, an emf is induced in the coil. This phenomenon is called electromagnetic induction. The emf induced due to electromagnetic induction is called induced emf.

Question 16.
Observe the figure.

(a) Write the angle of incidence. (1)
(b) Write the relation between the angle of incidence and the angle of reflection. (1)
Answer:
(a) Angle of incidence, i = 90 – 40 = 50°
(b) Angle of incidence = angle of reflection
i = r (by the law of reflection)

Question 17.
When an object is placed at a distance of 30 cm in front of the mirror, an image is obtained at 15 cm on the same side.
(a) Write the values of u and v according to the new cartesian sign convention. (1)
(b) Calculate the focal length of the given mirror. (1)
Answer:
(a) Distance of object, u = -30 cm
Distance of image, v = -15 cm
(b) Focal length of the mirror,

Question 18.
Light falls obliquely from one medium to another as shown in the figure.
[MN is the normal at the point of incidence]

Which of the given medium is the fastest medium for light? Justify your answer. (2)
Answer:
Medium A
Reason: From the figure, the angle of incidence is greater than the angle of refraction as optical density decreases light rays will move away from the normal. So medium A has low optical density. As optical density decreases, the speed of light through the medium increases.

Question 19.
DC is flowing through a solenoid AB. The direction of the current at the end A is anticlockwise.
(a) Write the polarity at the end A. (1)
(b) The solenoid is replaced by a current-carrying conductor. Give the name of the law that helps to determine the direction of the magnetic field produced. (1)
Answer:
(a) North Pole
(b) Maxwell’s right-hand thumb rule/Screw rule.

Question 20.
‘Green energy is the energy of the future’.
Explain the above statement based on the energy crisis. (2)
Answer:
The energy crisis is the consequence of increasing demand and decreasing availability of energy sources. So far future generations, green energy should be maximized since it is eco-friendly and created from nature, we can reduce pollution as well as reduce the use of fossil fuels.

Each question from 21 to 28 carries 3 scores.

Question 21.
2 A current flows through an electric heating device connected to a 230 V supply.
(a) The quantity of charge that flows through the circuit in 5 minutes is: (1)
(i) 10 C
(ii) 60 C
(iii) 600 C
(iv) 6 C
(b) What is the resistance of the device? (1)
(c) Calculate the power of the heating device. (1)
Answer:
(a) Charge Q = I × t
I = 2A
t = 5 m = 5 × 60 s
∴ Q = 2 × 5 × 60 = 600 C
Option (iii) is correct.

(b) R = \(\frac{V}{I}\)
= \(\frac{230}{2}\)
= 115 Ω

(c) P = I²R
= 2² × 115
= 460 W

Question 22.
Three resistances of 4 Ω, 6 Ω, and 12 Ω are given to you.
(a) What is the highest resistance that you can get using all of them? (1)
(b) What is the lowest resistance that can be obtained by using the 6 Ω and 12 Ω resistances? (2)
Answer:
(a) Resistors are connected in series,
R₁ = 4 Ω, R₂ = 6 Ω, R₃ = 12 Ω
R = R₁ + R₂ + R₃
= 4 + 6 + 12
= 22 Ω
(b) The lowest resistance can be made by connecting them parallel.
R₁ = \(\frac{R_1 R_2}{R_1+R_2}=\frac{6 \times 12}{6+12}=\frac{72}{18}\) = 4 Ω

Question 23.
The voltage of electric power generated is increased from 11 kV to 220 kV in power transmission. But the household supply is provided at 230 V.
(a) Write the type of transformer used at the first phase of power transmission. (1)
(b) Write the type of transformer used at the distribution line. (1)
(c) Write any two structural differences between the step-up and step-down transformer. (1)
Answer:
(a) Step up transformer (11 kV to 220 kV)
(b) Step down transformer (11 kV to 230 V)
(c) In step-up transformers, several turns in the primary are less than that in the secondary, and thick wires are used in the primary.
In step-down transformers, several turns in the primary are more than that in the secondary, and thin wires are used in the primary.

Question 24.
The graphical representation of EMF obtained from three electrical sources is given below.

(a) Identify any two sources. (1)
(b) Write any two peculiarities of each of the emf shown in the graph (A) and (B). (2)
Answer:
(a) A – AC generator
B – Battery
C – DC generator

(b) A: Direction changes continuously, emf increases and decreases.
B: Direction does not change, emf is constant.

Question 25.
(a) How fossil fuels are formed? (1)
(b) What are the products obtained by fractional distillation of coal? (2)
Answer:
(a) Fossil fuels are formed by the transformation of plants and animals that went under the earth’s crust millions of years ago. The transformation took place in the absence of air under high pressure and high temperature. Coal, petroleum, and natural gas are fossil fuels. They are not replenished.
(b) Ammonia, coal gas, coal tar, and coke are obtained.

Question 26.
A Rainbow is formed due to the dispersion of sunlight.
(a) What is dispersion? (1)
(b) Write down the changes in the sunlight in the water droplet as the rainbow forms. Explain. (2)
Answer:
(a) It is the splitting up of composite light into its constituent colors.
(b) When sunlight passes through water droplets, it undergoes refraction twice and internal reflection. The light ray emerging from the water droplets which makes the same angle with the line of vision have the same colour. These droplets appear in the form of an arch of a particular color. Thus there is a red colour in the upper edge and violet at the lower edge. All other colors are seen in between depending on their wavelengths.

Question 27.
The critical angle of water with air is shown in the figure.

(a) Define critical angle. (1)
(b) What change in the path of light will be observed if the angle of incidence Is increased from a critical angle? (1)
Answer:
(a) Critical Angle: When a ray of light passes from a medium of greater optical density to that of lower optical density, the angle of incidence at which the angle of refraction becomes 90° is the critical angle.
(b) All the incident rays will be reflected to the same medium without refraction.

Question 28.
The magnification of an image formed in a mirror is -1.
(a) What is the negative sign indicated with the value of magnification? (1)
(b) What is magnification? (1)
(c) Identify the mirror used. (1)
Answer:
(a) If magnification is negative, it means the image formed by the mirror is real and inverted.
(b) Magnification is defined as the ratio of the height of the image to the height of the object.

(c) Concave mirror

Each question from 29 to 34 carries 4 scores.

Question 29.
Observe the figure.

(a) Identify the Generator. (1)
(b) Write the working principle of this generator. (1)
(c) Which type of emf is induced in the armature? (1)
(d) Write the function of the split ring commutator used in this generator. (1)
Answer:
(a) DC generator
(b) Electromagnetic induction
(c) AC
(d) Split rings are used to convert AC into DC.

Question 30.
Analyze the figure to answer the questions.

(a) In which circuit is a varying magnetic field developed around the solenoid? (1)
(b) Which bulb in the circuit glows when the switch is kept on? (1)
(c) Explain whether there is a difference in the intensity of the light of the bulb. (2)
Answer:
(a) Figure B
(b) Both bulbs will glow, but the intensity of bulb B decreases.
(c) When both the switches are getting ON, a varying magnetic field is developed around the coil in fig (B) because of AC, a back emf is induced in it due to self-induction, and the effective voltage across the bulb decreases hence brightness of the bulb decreases.

Question 31.
(a) If the image obtained from a convex lens is erect and enlarged:
(i) Image is formed at: (1)
[Same side of the object/Opposite side of the object]
(ii) Write any one application of this type of image formation. (1)
(b) Write any two characteristics of the image formed by a convex lens when the object is placed at the following positions.
(i) At infinity. (1)
(ii) Between F and 2F. (1)
Answer:
(a) (i) Same side of the object.
(ii) Used in simple microscope/telescope/compound microscope/magnifier/reading lens etc.

Question 32.
Observe the circuit diagram and answer the questions.

(a) Find the effective resistance of the given circuit. (1)
(b) Calculate the current flowing through this circuit. (1)
(c) What is the heat produced in the 100 Ω resistance if the current flows for 10 minutes? (2)
Answer:
(a) R = R₁ + R₂
= 100 + 15
= 115 Ω
(b) I = \(\frac{V}{R}\)
= \(\frac{230}{115}\)
= 2 A
(c) H = I²Rt
= 2² × 100 × 10 × 60
= 240000 J

Question 33.
(a) Write the function of a safety fuse in an electric circuit. (1)
(b) Write any two characteristics of fuse wire. (1)
(c) Write any two precautions to be taken while including fuse wire in a circuit. (2)
Answer:
(a) When excess current flows through the circuit, the heat generated in the fuse wire becomes excessive and the fuse wire will melt, and the circuit will break hence it will protect the device from overcurrent.
(b) Low melting point, high ductility, correct amperage.
(c) The ends of the fuse wire must be connected firmly at appropriate points.
The fuse wire should not project out of the carrier base.

Question 34.
Observe the ray diagram given below.

(a) Redraw the diagram and complete it to get the image. (2)
(b) Write any two characteristics of the image obtained. (2)
Answer:
(a) Object beyond 2F.

(b) Inverted, real, diminished, between F and 2F.