8th Standard Basic Science Annual Exam Question Paper 2022-23 Kerala Syllabus

Practicing with Class 8 Basic Science Question Paper Kerala Syllabus and Annual Exam Question Paper 2022-23 will help students prepare effectively for their upcoming exams.

Class 8 Basic Science Annual Exam Question Paper 2022-23 Kerala Syllabus

Time: 2 hrs
Max. Score : 60

Instruction:

• The total cool off time for Physics, Chemistry and Biology is 15 minutes. Read the questions carefully and understand them during this time.
• Answers are to be written in the order Physics, Chemistry and Biology. The time for each section is 40 minute. The answer books must be returned to the teacher after writing each subject.

Physics

Time: 40 minute
Score: 20

Answer any THREE questions from 1 to 4. (Each question carries 1 score) (3 × 1 = 3)

Question 1.
Find the relation between the first word pair and complete the second pair suitably. (1)
Electric charge: coulomb::
Capacitance: _______
Answer:
Capacitance: farad

Question 2.
Choose the derived unit from the following. (1) (m, kg, N, s)
Answer:
N

Question 3.
Which-among the following statements is correct? (1)
a) Like poles attract each other.
b) Magnetic field is experienced in all directions around a magnet.
c) The direction of magnetic lines of force is from the south pole to the north pole outside the magnet.
Answer:
b) Magnetic field is experienced in all directions around a magnet.

Question 4.
Which type of spherical mirror always gives an erect and diminished image? (1)
Answer:
Convex mirror always gives an erect and diminished image.

Answer any 4 questions from 5 to 9. Each question carries 2 scores. (4 × 2 = 8)

Question 5.
When certain bodies are rubbed against one another, electron transfer takes place between them.
Complete the table give below on the basis of this concept. (2)

Pair of bodies used for rubbing	Body that loses electrons	Body that receives negative charge
Ebonite, Wool	(a)	(b)
Glass rod, Silk	(c)	(d)

Answer:
a) Wool
b) Ebonite
c) Glass rod
d) Silk cloth

Question 6.
Details of the journey of a car in a straight line are given as a line diagram. Analyse the information and answer the questions.

a) From C to D, the car has _______ (1)
(uniform acceleration/ non uniform velocity / uniform velocity)
b) Calculate the acceleration of the car from A to C. (1)
Answer:
a) uniform velocity

b) u = 0m/s
v = 10m/s
t = 10s

a = \(\frac{v-u}{t}=\frac{10-0}{10}=\frac{10 \mathrm{~m} / \mathrm{s}}{10 \mathrm{~s}}\)
= 1 m/s²

Question 7.
Production of sound in a manner unhealthy to human beings is noise pollution. “Let us reduce noise pollution.” – Prepare a poster to spread awareness in the society about this idea. (2)
Answer:

Question 8.
a) Copy the ray diagram and complete it showing the image formation. (1)

Answer:

b) Write down two properties of the image. (1)
Answer:
Real, inverted and of the same size.

Question 9.
Sounds with frequency greater than 20000 Hz. are called ultrasonics. Write down two uses of ultrasonic sound. (2)
Answer:

• Used in the instrument SONAR to measure the depth of the ocean.
• Used in the medical field for diagnosis and treatment.

Answer any 3 questions from 10 to 13. Each question carries 3 score. (3 × 3 = 9)

Question 10.
Uses of different types of mirrors are given. Classify and tabulate them.
a) As rear view mirrors in vehicles.
b) Head mirror used by doctors.
c) As reflector in solar concentrator.
d) As reflector in street lamps.
e) For viewing our face normally.
f) In film projectors, as reflector.

Concave mirror	___________
Plane mirror	___________
Convex mirror	___________

Answer:
Concave mirror
b) Head mirror used by doctors.
c) As reflector in solar concentrator.
f) In film projectors, as reflector.

Plane mirror
e) For viewing our face normally.

Convex mirror
a) As rear view mirrors in vehicles.
d) As reflector in street lamps.

Question 11.
Analyse the given situations i and ii and an-swer the followoing questions,
i) A coconut is falling from a coconut tree.
ii) A rolling ball comes to rest after moving some distance.
a) Which of these is an example of motion under non contact force? (1)
b) In which situation, the body has retardation? What is the reason for the retardation here? (1)
c) Write down another example for non contact force. (1)
Answer:
a) A coconut is falling from a coconut tree.
b) The body has a retardation, when a rolling ball comes to rest after moving some distance because the velocity is decreasing.
c) An iron nail getting attracted to a magnet. (The non-contact force here is the magnetic force).

Question 12.
Lightning conductors are fixed to protect tall buildings from the danger of lightning.
a) Pointed edges are used in lightning conductors. What is the scientific principle behind it? (1)
Answer:
The lightning conductors have pointed edges. Charge density will be greater at pointed edges.

b) Write down any other two precautions to protect ourselves when there is lightning. (2)
Answer:

• Do not operate electrical equipments.
• Do not stand holding window rails or grills.

Question 13.
Match the following appropriately. (3)

A	B	C
Atmospheric pressure	m/s	Decibel meter
Speed	dB	Speedometer
Loudness	bar	Barometer
	m/s2	Lactometer

Answer:

A	B	C
Atmospheric pressure	bar	Barometer
Speed	m/s	Speedometer
Loudness	dB	Decibel mete

Chemistry

Time: 40 minute
Score: 20

Answer any 3 questions from 1 to 4. Each carries 1 score. (3 × 1 = 3)

Question 1.
Which one of the following solids changes directly into gas without melting into liquid, on heating?
(Common salt, Sugar, Wax, Camphor) (1)
Answer:
Camphor

Question 2.
Fill up suitably (1)
Glucose: Monomer
Starch : _______
Answer:
Polymer

Question 3.
Complete the given chemical equation (1)
Mg + H₂O → MgO + ___
Answer:
Mg + H₂O → MgO + H₂

Question 4.
_______ is an elastic polymer
(Protein, Silk, Rubber, Jute)
Answer:
Rubber

Answer any 4 questions from 5 to 9. Each carries 2 scores. (4 × 2 = 8)

Question 5.
a) How many oxygen atoms are present in a molecule of sulphuric acid (H₂SO₄)? (1)
b) Determine the total number of atoms present in 5NH₃ (1)
Answer:
a) 4
b) 20

Question 6.
a) Write the name of the process by which copper is coated on an iron ring. (1)
b) This process is an electrochemical reaction. Give reason. (1)
Answer:
a) Electroplating
b) Electrical energy is absorbed during this chemical reaction.

Question 7.
a) Write the name of the metal used to make filament of electric bulb. (1)
b) Which property of the metal is utilised here?
(Sonority, Ductility, Metallic lustre) (1)
Answer:
a) Tungsten
b) Ductility

Question 8.
Identity the property of water shown in each of the following situations.
a) Water is used in radiators of automobiles. (1)
b) Small water drops assume spherical shape. (1)
Answer:
a) High heat capacity
b) Surface tension

Question 9.
Which of the following characteristics are related to synthetic fibres? (2)
a) Can be dried easily on getting wet
b) High aeration
c) Low durability
d) Wrinkle free
Answer:
Can be dried easily on getting wet wrinkle free.

Answer any 3 questions from 10 to 13. Each carries 3 scores. (3 × 3 = 9)

Question 10.
Analyse the table and answer the questions given below.

Mixture A	Mixture B	Mixture C
Particles cannot be separated by filtration	Particles can be separated filtration	Particles cannot be separated by filtration
On passing an intense beam of light, its path is visible		On passing an intense beam of light, its path is not visible

a) Which one of the given mixtures repre-sents a true solution? (1)
b) In the mixture particles settle down when kept undisturbed for some time? (1)
c) To which of these mixtures does milk belong? (1)
Answer:
a) Mixture C
b) Mixture B
c) Mixture A

Question 11.
Two samples of water are given.
Sample 1 – Soap gives lather easily.
Sample 2 – Soap does not give lather easily.
a) Which sample represents hard water?
b) Which among the following salts causes hardness of water? (1)
(Sodium carbonate, Magnesium chloride, Zinc hydroxide, Ammonium chloride)
c) Which type of hardness of water can be removed by boiling? (1)
Answer:
a) Sample – 2
b) Magnesium Chloride
c) Temporary hardness

Question 12.
Thermoplastics and thermosetting plastics are two types of plastics.
a) How do they differ? (2)
b) Choose the thermosetting plastic from the following.
(Polythene, Bakelite, PVC, Rubber)
Answer:
a) On heating thermoplastics become soft and on cooling it becomes hard. This process can be repeated several times. At the time of manufacture thermo setting plastics becomes soft on heating. But on cooling it becomes hard permanently,
b) Bakelite

Question 13.
Water pollution is a burning issue now-a-days.
a) How do aquatic animals and plants get oxygen for respiration? (1)
b) The wastes dumped into rivers and ponds result in the destruction of acquatic life. Explain. (1)
c) Write any other activity that causes water pollution. (1)
Answer:
a) Aquatic animals and plants respire dissolved oxygen in water.
b) When wastes are dumped in water, it use up dissolved oxygen for decomposition. This destruct aquatic life.
c) Chemical fertilizers and pesticides are washed off by rain into water sources.

Biology

Time: 40 minute
Score:20

Answer any 3 from questions 1 to 4. Each question carries 1 score. (3 × 1 = 3)

Question 1.
Choose the cell organelle which is seen in plenty in glandular cells. (1)
a) Mitochondrion
b) Ribosome
c) Golgi complex
d) Endoplasmic reticulum
Answer:
c) Golgi complex

Question 2.
Identify the word pair relation and fill in the blank. (1)
Ovary: Estrogen
Testis: _______
Answer:
Testis – Testosterone

Question 3.
Identify the odd one and write the common feature of others. (1)
a) Nilgiri Tahr
b) Lion-tailed macaque
c) Dodo
d) Malabar civet cat
Answer:
c) Dodo – others are organisms on the verge of extinction.

Question 4.
Choose the correct pairs from the following. (1)

Community Reserves – Peppara National Parks – Silent Valley Biosphere reserves – Wayanad Wild Life Sanctuary – Periyar

Answer:
Rubber

Answer any 4 from questions 5 to 9. Each questions carries 2 score. (4 × 2 = 8)

Question 5.
Correct the mistake if any in the underlines part of the given statements. (2)
a) Zoological gardens are example of insitu conservation.
b) Community reserves are areas protected with the participation of the public.
c) Biosphere reserves are designed to protect wild lives along with the protection of historical monuments natural resources etc of an area.
Answer:
a) Ex-situ conservation
c) National Parks

Question 6.
Analyse the statement and answer the questions.

The scientific name of dog is Canis familaris

a) How is this method of giving scientific names to organisms known as? (1)
b) What does the words Canis and familiaris in the scientific name indicate? (1)
Answer:
a) Binomial nomenclature
b) Canis – indicates the name of the genus familiaris – indicates the name of the species.

Question 7.
Analyse the new report and answer the questions.
The Ministry of Health has launched a project to supply iron tablets to 13 crores of students coming under the age group of 10-19 years.
a) This project is launched to cure which disease? (1)
b) What is the role of food habits to overcome this situation? (1)
Answer:
a) Anaemia
b) It is due to deficiency of iron. So, the person must food containing iron.

Question 8.
Observe the figure and answer the questions.

a) Identify the parts labelled as X and Y in the figure. (1)
b) Write the function of X (1)
Answer:
a) X – Vas deferens
Y – Testis

b) X – Vas defems
Carries the sperms that are formed in the testes to the Ureter.

Question 9.
Analyse the statements given below and give reasons for each.
a) One of the most important ecological hotspots in India is western ghats. (1)
b) Sacread groves are to be protected and maintained. (1)
Answer:
a) Western Ghats are areas rich in endemic species but having the threat of habitat destruction.
b) Sacred groves are small areas of biodiversity protected in regions inhabited by human beings. It play an important role in the conservation -of water in the region too.

Answer any 3 from questions 10 to 13. Each questions carries 3 score. (3 × 3 = 9)

Question 10.
Analyse the illustration and complete it.

Answer:
a) Commensalism
b) Mutualism
c) Beneficial to both the organisms.
d) Beneficial to one, harmful to the other.
e) Mango tree and Vanda.
f) Tiger and Deer

Question 11.
Redraw the diagram, identify and label the parts mentioned below.

a) The part which transforms into endosperm after fusing with the male gamete. (1)
b) The part which develops from pollen grain and grows towards the ovary. (1)
Answer:

Question 12.
Some of the services that biodiversity provide us are given below. Analyse them and complete the following table.

• O₂ – CO₂ balance
• Pollination
• Nutrient recycling
• Soil formation
• Climate control

Auxiliary service	_________

Answer:

Auxiliary services	Ecological services
Nutrient cycling	O2, CO2 balance
Pollination	Soil formation
Climate control

Question 13.
Complete the given table suitably.

Gametes	Characteristics
	Size	Motility	Morphology
a)…..	…(b)….	Yes	….(c)….
Ovum	…(d)…	(e)…	….(f)…

Answer:
a) Sperm
b) Small in size
c) Head, middle piece and tail
d) Larger in size
e) Non motile
f) Spherical in structure