Kerala Plus One Computer Science Board Model Paper 2023 with Answers

Reviewing Kerala Syllabus Plus One Computer Science Previous Year Question Papers and Answers Pdf Board Model Paper 2023 helps in understanding answer patterns.

Kerala Plus One Computer Science Board Model Paper 2023 with Answers

Time: 2 Hours
Total Score: 60 Marks

Answer any 5 questions from 1 to 6. Each carries 1 score. (5 × 1 = 5)

Question 1.
Which is the MSB representation of – 90 in the sign magnitude representation method?
Answer:
1

Question 2.
Which flowchart symbol is always used in Pair?
Answer:
Connector symbol

Question 3.
Name a ternary operator in C++.
Answer:
conditional operator

Question 4.
________ is the built in function used to terminate the program.
Answer:
exit()

Question 5.
Expand the term Wi-MAX.
Answer:
Worldwide Interoperability for microwave access

Question 6.
Acquiring information such as username, password, credit card detrails etc. using misleading websites is known as ……………………
Answer:
Phishing

Part – II

Answer any 9 questions from 7 to 18. Each carries 2 scores. (9 × 2 = 18)

Question 7.
One of the following number is invalid, find it and state the reason for invalidity.
Answer:
(a) (101001)₈
(b) (111)₂
(c) (768)₈
(d) (ABC)₁₆
Answer:
(c) (768)₈
(768)₈ is invalid because the number 8 will not be used in Octal number system.

Question 8.
Write any 2 differences between RAM and ROM.
Answer:

RAM	ROM
• It allows reading and writing.	• Allows reading only.
• It is volatile.	• Non-volatile.

Question 9.
Draw a flowchart to find the biggest of two numbers.
Answer:

Question 10.
Find the invalid identifier names from the following and give the reason for invalidity.
-8AC Z$ B7 for INT
Answer:
Z$ – $ Symbol is not allowed
for – Keyword is not allowed

Question 11.
What is L-value and R-value of a variable?
Answer:
L – value is the address and
R – value is the content of the variable

Question 12.
Compare entry controlled loop with exit controlled loop.
Answer:

Entry controlled loop	Exit controlled loop
• No guarantee to execute at least once. E.g. for, while	• Execute at least once. E.g. do while

Question 13.
List the name of any 4 operations that can be performed on an array.
Answer:
Traversing, Searching, Insertion, Deletion.

Question 14.
Write an algorithm for linear search.
Answer:
Step 1 : Start
Step 2 : Read the search element, say x
Step 3 : Compare the x with the first element.
Step 4 : if not matched, complare with the next element
Step 5 : if matched, display “element found” and go to last step
Step 6 : Repeat step 3 and 4 until the last element
Step 7 : if no match, print “Element is not found”
Step 8 : Stop

Question 15.
Distinguish between call by value and call by reference method.
Answer:

Call by value method	Call by reference method
Ordinary variables are used as formal parameters.	Reference variables are used as formal parameters.
The changes made in the formal arguments do not reflect in actual arguments.	The changes made in the formal arguments to reflect inactual arguments.

Question 16.
List the name of any 4 character functions in C++.
Answer:
isupper(), islower(), isalpha(), isdigit()

Question 17.
List and explain any 2 advantages of computer networks.
Answer:
Need for network
The advantages of Networks are given below.

1. Resource sharing: All the computers in a network can share software (programs, data …………) and hardware (printer, scanner, CD drive etc.).
2. Reliability : If one computer fails, the other computer can perform the work without any delay. This is very important for banking, air traffic control and other application.
3. Price Vs Performance: A main frame computer can be 10 times faster than a PC but it costs thousand times a PC. Therefore instead of a main frame 10 personal computers are used with less cost and same performance.
4. Communication Medium : It is a powerful communication medium. We can exchange information between computers in a network.
5. Scalable: This means, System performance can be increased by adding computers to a network.

Question 18.
Write any 4 advantages of social media.
Answer:
Social Media helps to :

1. Bring people together
2. Plan and organize events
3. Business promotion
4. Social Skills

Part – III

Answer any 9 questions from 19 to 29. Each carries 3 scores. (9 × 2 = 18)

Question 19.
Match the following:

a. ABACUS	1. Charles Babbage
b. Napier’s Bones	2. Wheels and Gears
c. Pascaline	3. Counting Frame
d. Leibnitz’s Calculator	4. Punched Card
e. Jacquard’s Loom	5. Numbering Rods
f. Analytical Engine	6. Step Reckoner

Answer:

a. ABACUS	5. Numbering Rods
b. Napier’s Bones	2. Wheels and Gears
c. Pascaline	4. Punched Card
d. Leibnitz’s Calculator	6. Step Reckoner
e. Jacquard’s Loom	1. Chrles Babbage
f. Analytical Engine	3. Counting Frame

Question 20.
Construct a logical circuit for the expression
f (a, b) = (a + b) . (\(\overline{\mathrm{a}}\) + \(\overline{\mathrm{b}}\))
Answer:

Question 21.
Categorize the software given below into operating system, application software and utility program.
Answer:
Ubuntu, Open Office Calc, Windows, WinZip, GIMP, Kaspersky
Answer:

OS	Application software	Utility program
Ubuntu, Windows	Open Office Calc, GIMP	WinZip, Kaspersky

Question 22.
Explain the different types of errors that are occurred during the compilation and running of a program.
Answer:
There are two types of errors in a program before execution and testing phase.They are syntax error and logical error. When the programmer violates the rules or syntax of the programming language then the syntax error occurred. Eg: It involves incorrect punctuation. Key words are used for other purposes, violates the structure etc,… It detects the compiler and displays an error message that include the line number and give a clue of the nature of the error. When the programmer makes any mistakes in the logic, that types of errors are called logical error. It does not detect by the compiler but we will get a wrong output. The program must be tested to check whether it is error free or not. The program must be tested by giving input test data and check whether it is right or wring with the known results. The third type of errors are Runtime errors. This may be due to the in appropriate data while execution. For example consider B/C. If the end user gives a value zero for c, the execution will be interrupted because division by zero is not possible. These situation must be anticipated and must be handled.

Question 23.
Explain any 3 Tokens available in C++.
Answer:
Token: It is the smallest individual units similar to a word in English or Malayalam language. C++ has 5 tokens
1) Keywords: These are reserved words for the compiler. We can’t use for any other purposes Eg: float is used to declare variable to store numbers with decimal point. We can’t use this for any other purpose

2) Identifier: These are user defined VvdtdS. Eg: variable name, function name, class narrle; Pbject name etc…

3) Literals (Constants): Its value does not change during execution
1) Integer literals -: Whole numbers without fractional parts are known as integer literals, its value does not change during execution. There are 3 types decimal, octal and hexadecimal.
Eg. For decimal 100, 150, etc
For octal 0100, 0240, etc
For hexadecimal 0 × 100,0 × 1 A,etc

2) Float literals -: A number with fractional parts and its value does not change during execution is called floating point literals.
Eg. 3.14157, 79.78, etc

3) Character literal-: A valid C++ character enclosed in single quotes, its value does not change during execution.
Eg. ‘m’, ‘f ’ etc

4) String literal -: One or more characters enclosed in double quotes is called string constant. A string is automatically appended by a null character(‘\0’)
Eg. “Mary’s”,’’India”,etc

Question 24.
Write another 3 forms of the C++ statement a = a +1;
Answer:
a++; ++a; a+=1;

Question 25.
What is the role of relational operators in C++? Distinguish between == and =
Answer:
== is an relational operator. It is used for comparing two expressions in C++. -’ is an assignment operator
Used to assign values from RHS to LHS.

Question 26.
Distinguish between break and continue statements in C++.
Answer:

Break	Continue
Used with switch or loops	Used only with loops
Takes the control outside the Loop	Does not take control out of loop
Causes to terminate the loop	Skips one iteration of the loop

Question 27.
Differentiate between put ( ) and write ( ) with an example.
Answer:
Output function: The outputt functions like put() (to print a character on the screen) and write() (to print a line of characters on the screen) is used with cout and dot(.) operator.

Function	Example	Description	Header file
put()	cout.put(ch) cout.put(‘a’)	To print a character on the screen	iostream
write()	cout. write (str, len)	To print a string with specified length on the sreen	iostream

Question 28.
Write a short note on any 3 network topologies.
Answer:
Bus topology – In bus topology all the nodes are connected to a main cable called bus. A small device called a terminator is attached to each end of the bus.

Star topology – In star topology each node is directly connected to a hub switch.

Ring topology in ring topology all nodes are connected using a cable that shapes like a ring or circle Data travels only in one direction in a ring.

Question 29.
Explain about the following social medias.
a) Internet Forums
b) Content communities
c) Micro blogs
Answer:
a) Internet forums : It is an online discussion site where people can exchange information about various issues like social, political, educational etc. in the text form.
b) Content communities. By using these websites we can share multi media files.
Eg. www.youtube.com
c) Microblogs : It allows users to exchange short messages, multi media files etc.
Eg. www.twitter.com

Part – IV

Answer any 2 questions from 30 to 32. Each carries 5 scores. (2 × 5 = 10)

Question 30.
(a) Explain any 3 methods of representing integer numbers in computer memory? (3)
(b) Find the one’s complement of – 38 (2)
Answer:
(a) There are three ways to represent integers in computer. They are as follows:
1) Sign and Magnitude Representation (SMR)
2) 1’s Complement Representation
3) 2’s Complement Representation

1) SMR: Normally a number has two parts sign and magnitude, eg:- Consider a number +5. Here + is the sign and 5 is the magnitude. In SMR the most significant Bit (MSB) is used to represent the sign. If MSB is 0 sign is +ve and MSB is 1 sign is-ve.
eg :- If acopiputer has word size is 1 byte then

+5 is represented as

0

0

0

0

0

1

0

1

-5 is represented as

1

0

0

0

0

1

0

1

Here MSB is used for sign then the remaining 7 bits are us£d to represent magnitude. So we can represent 27 = 128 numbers. But there are negative and positive numbers. So 128 + 128 = 256 number. The numbers are 0 to +127 and 0 to -127. Here zero is repeated. So we can represent 256 – 1 = 255 numbers.

2) 1’s Complement Representation: To get the 1 ’s complement of a binary number, just replace every 0 with 1 and every 1 with 0. Negative numbers are represented using 1’s complement but +ve number has no 1 ’s complement.
eg:- To find the 1’s complement of-21
+21 = 00010101
To get the 1 ’s complement change all 0 to 1 and all 1 to 0.
-21 = 11101010
∴ 1’s complement of -21 is 11101010
Eg: Find the 1’s complement of +21
Positive numbers are represented by using SMR.
+21 = 00010101 (No need to take the 1’s complement)

3) 2’s Complement Representation : To get the 2’s complement of a binary number, just add 1 to its 1’s complement +ve number has no 2’s complement.
eg:- To find the 2’s complement of -21
+21 =00010101
First take the 1 ’s complement for this change all 1 to 0 and all 0 to 1

∴ 2’s complement of-21 is 1110 1011

(b) (38)₁₀ = (100110)₂
So +38 = 00100110
One’s complement of-38 is 11011001
Changed all ones to zero and all zeros to one.

Question 31.
(a) What do you mean by e-Waste? (1)
(b) Explain any 4 methods of disposing e-Waste? (4)
Answer:
(a) e-Waste(electronic waste): It refers to the mal functioning electronic products such as faulty computers, mobile phones, TV sets, toys, CFL etc.

(b) e-Waste disposal methods
a) Reuse: Reusability has an important role of e-Waste management and can reduce the volume of e-Waste
b) Incineration: It is the process of burning e-Waste at high temperature in a chimney
c) Recycling of e-Waste : It is the process of making new products from this e-Waste.
d) Land filling: It is used to level pits and cover by thick layer of soil.

Question 32.
(a) Name and explain the different types of loops in C++. (3)
(b) Rewrite the following program using while loop. (2)
main( )
{
int a, p -1;
for (a = 1; a<=5; a+<2)
P=P*a;
cout<<p;
}
main( )
{
int a, p – 1;
for (a = 1; a<=5; a+<2)
p=p*a;
cout<<p;
}
Answer:
1. while statement
It is an entry controlled loop. An entry controlled loop first checks the condition and execute(or enters in to) the body of loop only if it is true. The syntax is given below
Loop variable initialised
while(expression)
{
Body of the loop;
Update loop variable;
}
Here the loop variable must be initialised before the while loop. Then the expression is evaluated if it is true then only the body of the loop will be executed and the loop variable must be updated inside the body. The body of the loop will be executed until the expression becomes false.

2. for statement
The syntax of for loop is
for(initialization; checking ; update loop variable)
{
Body of loop;
}
First part, initialization is executed once, then checking is carried out if it is true the body of the for loop is executed. Then loop variable is updated and again checking is carried out this process continues until the checking becomes false. It is an entry controlled loop.

3. do – while statement : It is an exit controlled loop. Exit control loop first execute the body of the loop once even if the condition is false then check the condition.
do
{
Statements
}while(expression);
Here the body executes at least once even if the condition is false. After executing the body it checks the expression if it false it quits the body otherwise the process will be continue.

b)
main()
{.
int a=1,p=1;
while(a<=5)