Kerala Plus One Computer Science Board Model Paper 2021 with Answers

Reviewing Kerala Syllabus Plus One Computer Science Previous Year Question Papers and Answers Pdf Board Model Paper 2022 helps in understanding answer patterns.

Kerala Plus One Computer Science Board Model Paper 2021 with Answers

Time: 2 Hours
Total Score: 60 Marks

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

Question 1.
(a) Who is known as father of computer ?
(b) The pictorial representation of algorithm is known as _____________ .
(c) The ___________ operator gives the remainder value during arithmtic division in C++.
(d) In C++ array index or subscript starts with _____________ .
(e) In C++, ___________ function is used to find the square root of a number.
Answer:
a. Charles Babbage
b. Flowchart
c. % Or Modulus Operator Or MOD
d. 0
c. sqrt()

Answer any 11 questions from 2 to 19. Each carries 2 scores. (11 × 2 = 22)

Question 2.
(a) 1 Byte = ____________ Bits
(b) 1 GB = 1024 ___________ .
Answer:
(a) 8
(b) MB or Mega Bytes

Question 3.
Prepare a short note on any one e-Waste disposal method.
Answer:

1. Reuse -Second hand use or usage after the equipment has been upgraded or modified.
2. Incineration -burn at high temperature
3. Recycle -making new products from old one
4. Land filling -buried in the soil

Question 4.
What is cache memory ?
Answer:
It is a high speed memory placed in between RAM and processor. It enhances the speed. Eg. L1, L2,…

Question 5.
Compare logical errors and syntax errors.
Answer:
Syntax error occurs due to violation of rules or syntax of the programming language .It will be displayed. Error in the logic of the program is called Logical error, it is due to the improper planning. Hence it gives incorrect output.

Question 6.
Write any two advantages of flow chart.
Answer:
Any two from the following

1. Better communication
2. Effective analysis
3. Effective synthesis
4. Efficient coding

Question 7.
List out the literals in C++.
Answer:

1. Integer literal
2. Floating point literal
3. Character literal
4. String literal

Question 8.
Describe about any two fundamental data types in C++.
Answer:
Any two from the following

Question 9.
Compare break and continue statements in C++.
Answer:
break-: It is used for premature termination from the loop or switch.
continue-: It bypasses(skips) one iteration and continue the iteration with next value.

Question 10.
Write C++ statement to declare an array to store 10 integer values.
Answer:
int n[10];

Question 11.
Write short note on getline().
Answer:
getline()-: It is used to read a string from the console(keyboard).
Eg. cin.getline(str.len);
cin.getline(str,len,ch);

Question 12.
What is the use of write( ) function in C++ ?
Answer:
Write()-: It is used to display a string on the monitor.

Question 13.
Briefly explain function argument in C++.
Answer:
Arguments are the values passing to the function while it is calling.

Question 14.
Write the names of any two character functions in C++.
Answer:
Any two character functions from the following

1. islower()
2. isupper()
3. isdigit()
4. isalpha()
5. isalnum()
6. tolower()
7. toupper()

Question 15.
Write the name of string functions used for the following purposes:
(a) To find the length of a string.
(b) To compare two strings.
Answer:
(a) strlen()
(b) strcmp() or strcmpi()

Question 16.
Write short note on :
(a) Modem
(b) Switch
Answer:
(a) Modem:

• It is a device used to connect a computer to the internet.
• Its name derived from modulator and demodulator.
• Modem converts digital signals to analog signals(modulation) and analog signals to digital signals(demodulation)

(b) Switch:
• Switch is an intelligent device used to connect computers devices of the same network.

Question 17.
Discuss about the advantages of Social Media.
Answer:
Any two points from the following :

1. Bring people together
2. Plan and organise events
3. Business promotions
4. Social skills

Question 18.
What is computer virus?
Answer:
Virus is a bad program used to corrupt or delete, data from our computer.

Question 19.
Write short note on hacking.
Answer:
Hacking is a technical effort to manipulate the normal behaviour of network connections and connected systems. The person who performed this is called hackers. Eg. White hats, Black hats and Grey hats

Answer any 10 questions from 20 to 39. Each carries 3 scores. (10 × 3 = 30)

Question 20.
Explain Fourth generation computers.
Answer:
Any three points from the following

1. Microprocessors were used
2. They are also called microcomputers.
3. They use Very Large Scale Integration VLSI () technology.
4. A microprocessor consists of millions of transistors and components.
5. Semiconductors were used as main memory.
6. Fourth generation computers were more portable and reliable.

Question 21.
Write a short note on representation of integer numbers in computer memory.
Answer:

• Sign and magnitude representation(SMR): In SMR the MSB is used for representing sign,1 for -ve and 0 for +ve and the remaining bits for its magnitude.
• 1’s complement representation-: In this method replace all 1 by 0 and 0 by 1.
• 2’s complement representation-: 2′ s complement representation can be calculated by Adding 1 to 1’s complement representation.

Question 22.
briefly explain principle of duality.
Answer:

• There will be a dual for every Boolean expression
• It is obtained by replacing every AND with OR and every OR with AND
• It is also obtained by replacing 1 with 0 and 0 with 1

Question 23.
Prepare a short note on RAM.
Answer:
Any three from the following

1. Random Access Memory
2. temporary memory
3. volatile memory / data is lost when power is off
4. stores data , instruction , results etc

Question 24.
Differentiate between Primary Memory and Secondary Memory.
Answer:
Primary memory holds data, intermediate results and results of ongoing jobs temporarily.
Eg: Any one from (RAM, ROM, Cache)
Secondary memory holds data and information permanently.
Eg: Any one from (Hard disk, CD, DVD, Pen drive etc)

Question 25.
Draw the flow chart to find the area of a circle.
[Hint area = 3.14 × r²]
Answer:

Question 26.
List out the stages of phases in programming.
Answer:

1. Problem identification
2. Algorithm and flowchart
3. Program coding
4. Translation
5. Debugging
6. Execution and testing
7. Documentation

Question 27.
Categorise the following identifiers as valid or invalid.
sum, 1a, Class No,
reg-no, int, a * b
Answer:
Valid identifiers – sum
Invalid identifier – 1a , class No , reg-no , int, a*b

Question 28.
Briefly explain about structure of a C++ program.
Answer:

# include <iostream> /#include<header file>
using namespace std ; 
int main ()
{
statements
}

Syntax:
if (test expression)
{
statement block ;
}

Syntax:
lf(test expression)
{
statement block;
}
else
{
statement block;
}

# < include <iostream>
using namespace std ;
int main ()
{
int n, A[20] , i ,s=0;
cout<<“Enter the limit”; 
cin>>n;
cout<<“Enter the numbers”;
for( i=0 ; i<n; i++) 
{ 
cin>>A[i];
s= s+A[i];
}
cout<<“sum is “<<s;
}