Plus One Computer Science Improvement Question Paper Say 2018

Kerala Plus One Computer Science Improvement Question Paper Say 2018 with Answers

Time Allowed: 2 hours
Cool off time: 15 Minutes
Maximum Marks: 60

General Instructions to Candidates:

• There is a ‘cool off time’ of 15 minutes in addition to the writing time of 2 hours.
• Use the ‘cool off time’ to get familiar with the questions and to plan your answers.
• Read questions carefully before you answering.
• Read the instructions carefully.
• Calculations, figures, and graphs should be shown in the answer sheet itself.
• Malayalam version of the questions is also provided.
• Give equations wherever necessary.
• Electronic devices except non-programmable calculators are not allowed in the Examination Hall.

Answer all questions from 1 to 5. Each carry 1 score. (5 × 1 = 5)

Question 1.
Name the keyword that indicates an empty set of data.
Answer:
void

Question 2.
……… built-in function is used to terminate the program.
Answer:
exit(0)

Question 3.
Name the ancient number system with the largest base.
Answer:
Sumerian / Babylonian number system

Question 4.
In ………… network topology, each node is directly connected to a hub/switch.
Answer:
star topology

Question 5.
Name the character function used to accept a string including whitespace.
Answer:
gets() o rgetline()

Answer any 9 questions from 6 to 16. Each carries 2 scores. (9 × 2 = 18)

Question 6.
What are the characteristics of fourth generation computers?
Answer:
Characteristics are given below

• Micro processors are used
• The size of the computer is reduced much
• Speed increases
• Cost decreases
• More used friendly

Question 7.
Draw the truth table of NAND gate.
Answer:
Truth table of NAND gate is given below

Question 8.
What are the major functions of operating system?
Answer:
Process management, Memory handling, Device management and file management.

Question 9.
Write an algorithm to find the sum and average of three numbers.
Answer:
Step 1 : Start
Step 2 : Read 3 numbers n1, n2 and n3
Step 3 : sum=n1+n2+n3
Step 4 : avg=sum/3
Step 5 : Print Sum,Avg
Step 6 : Stop

Question 10.
What is meant by tokens? Name the 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.
Keywords, Identifier, Literals (Constants), Punctuators and Operators.

Question 11.
What is the use of the keyword “Const”? Give an example.
Answer:
The keyword const is used to declare constants in a program. Its value doesn’t change during execution. Eg. const float pi = 3.1415

Question 12.
Illustrate the memory allocation for a single dimensional array in C++.
Answer:

Question 13.
Consider the following statements.
Char name [20];
Cin>>name;
Cout<<name;
What will be the output if you input the string “GREEN COMPUTING”? Justify your answer.
Answer:
The output is GREEN. This is because of cin statement that will take upto the space. Here space is the delimiter. To resolve this gets() function can be used. To use gets() and puts() function the header file cstdio must be included.

Question 14.
Correct the program and write the output.
#include<iostream>
using namespace std;
int main ()
{
int n = 25;
float b = sqrt (n);
cout<<b;
return 0;
}
Answer:
use mathematical built in function the header file cmath must be included.
#include<cmath>
The output is square root of 25 is 5

Question 15.
Write a short note on WiMAX.
Answer:
Wi MAX (Wireless Microwave Access): It uses microwaves to transmit information across a network in a range 2 GHz to 11 GHz over very long distance.

Question 16.
Name any four Mobile Operating Systems.
Answer:
Popular Mobile OSs are Android from Google, iOS from Apple, BlackBerry OS from BlackBerry and Windows Phone from Microsoft.

Answer any 9 questions from 17 to 27. Each carries 3 scores. (9 × 3 = 27)

Question 17.
Fill in the blanks.
a) (……….)₁₀ = (11001)₂
b) (0.625)₁₀ = (………)₂
c) (AB)₁₆ = (……….)₂
Answer:
a) 25
b) (0.101)₂
c) (10101011)₂

Question 18.
a) MIDI stands for (1)
b) Draw the logical circuit for the Boolean expression. \(\overline{\mathrm{A}}\).B+A \(\overline{\mathrm{B}}\) (2)
Answer:
a) Musical Instrument Digital Interface
b)

Question 19.
a) The fastest memory in a computer is …………
b) Categorize the software given below into operating system, application package and utility program. Linux, Open Office Calc, Windows, WinZip, Kaspersky, OpenOffice Writer
Answer:
a) Register
b) OS – Linux, Windows
Application – Open Office calc, Open Office writer
Utility Programs – Winzip, Kaspersky

Question 20.
a) Program written in HLL is known as …………
b) What is the need of documentation for a program?
Answer:
a) Source Code

b) There are 2 types of documentation they are internal and external documentation.
Internal Documentation: We can write comments in the source code as part of documentation that helps to modify the program in future. It is known as internal documentation.

External Documentation: This includes preparation of system manual and user manual containing the functioning of the system, its requirements, installation, etc.

Question 21.
a) What is an algorithm?
b) Distinguish between logical error and syntax error in a program.
Answer:
a) Step by step procedure to solve a problem is called algorithm.

b) In general there are two types of errors syntax errors and logical errors. When the rules or syntax of the language are not followed then syntax errors occurred and it is displayed after compilation. .When the logic of a program is wrong then logical errors occurred and it is not displayed after compilation but it is displayed in the execution and testing phase.

Question 22.
a) Arrange the fundamental data types in ascending order of their memory requirement. (1)
b) What is the use of size of operator in C++? Give an example. (2)
Answer:
a) char, int/float, double
b) size of( ): This operator is used to find the size used by each data type.
Eg. size of(int)gives 4

Question 23.
Explain the looping statements in C++.
Answer:
Iteration statements: If we have to execute a block of statements more than once then iteration statements are used.

1) while statement
It is an entry controlled loop. An entry controlled loop first checks the condition and execute(or enters into) 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 checkthe 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 wiil be continue.

Question 24.
An array AR contains the elements 15, 81, 63, 25, 45, 58, 90. Illustrate the working of binary search technique to locate the element 45.
Answer:
Binary search can be performed only on sorted arrays. So the given array AR to be sorted by using bubble sort or selection sort. So the sorted array is as follows.
15, 25, 45, 58, 63, 81, 90
Step I: First we check the element with the middle element.
Here I = 0 and u = 6
m = (I + u)/2 = 3
Here the element AR[3] is 58,
It is greater than the element to be searched i.e. 45
So the upper bound is m – 1
i.e. u = 3 – 1 = 2
Step 2: again find m.
m = (I + u)/2 = (0 + 2)/2 – 1
Here the element AR[1] is 25.
It is less than the element to be searched i.e. 45
So the lower bound is m + 1
i.e. I = 1 + 1 = 2
Step 3: Again find m
m = (I + u)/2 = (2 + 2)/2 = 2
Here the element AR[2] is 45
The element is found and hence the search is finished.

Question 25.
Illustrate the working of bubble sort method for sorting the elements 23, 52, 43, 61, 73 and 28 in ascending order.
Answer:
Bubble sort
Consider the first 2 elements of the numbers and compare it.
23 is less than 52. So no need to interchange both of them. Then the numbers are 23, 52, 43, 61, 73, 28.
Next compare 52 and 43. Here 52 is greater.
So interchange both of them. Then the numbers are 23,43,52,61,73,28.
Next compare 52 and 61. Here 52 is leaser.
So no need to interchange.
Next compare 61 and 73. Here also no need to interchange.
Next compare 73 and 28. Here 73 is greater.
So interchange both of them. After the first phase the largest number is on the right side.
The numbers are as follows 23, 43, 52, 61, 28, 73.
Similarly do the remaining numbers except 73.
At last we will get the result as follows
23,28,43,52,61,73.

Question 26.
Distinguish between exit ( ) function and return statement.
Answer:
Both are used to terminate the program but both are different. Return is a keyword and exit(0) is a function.The difference is, we can use more than one exit(0) function but we can use only one return statement in a scope. To use exit(0), the header file cstdlib should be used.

Question 27.
a) Write the name of any two header files used in C++programs.
b) Write the role of header files in C++ programs.
Answer:
a) iostream, cstdio, cmath, cstring, etc
b) Header files help us to include the associate files that needed in our program.

Answer any 2 questions from 28 to 30. Each carries5 scores. (2 × 5 = 10)

Question 28.
a) 1 Byte = …….. Bits.
b) Explain the various types of memories in a computer system.
Answer:
a) 8 bits

b) Memory:
A computer has huge storage capacity. It is used to store data and instructions before starts the processing. Secondly it stores the intermediate results and thirdly it stores information(processed data), that is the final results before send to the output unit(Visual Display Unit, Printer, etc)

Two Types of storage unit:
i) Primary Storage alias Main Memory: It is further be classified into Two – Random Access Memory (RAM) and Read Only Memory (ROM). The one and only memory that the CPU can directly access is the main memory at a very high speed. It is expensive hence storage capacity is less.

RAM is volatile (when the power is switched off the content will be erased) in nature but ROM is non-volatile,(It is permanent). In ROM a “boot up” program called BIOS (Basic Input Output System) is stored to “boots up” the computer when it switched on. Some ROMs are given below.

• PROM
• EPROM
• EEPROM

ii) Secondary Storage alias Auxiliary Memory: Because of limited storage capacity of primary memory its need arises. When a user saves a file, it will be stored in this memory hence it is permanent in nature and its capacity is huge. Eg: Hard Disc Drive (HDD), Compact Disc (CD), DVD, Pen Drive, Blu Ray Disc etc.
i) Magnetic storage device: It uses plastic tape or metal/plastic discs coated with magnetic material.

• Hard Disk

ii) Optical storage device.
Optical Disk: The high power laser uses a concentrated, narrow beam of light, which is focuses and directed with lenses, prisms and mirrors for recording data. This beams burns very very small spots in master disk, which is used for making molds and these molds are used for making copies on plastic disks. A thin layer of aluminium followed by a transparent plastic layer is deposited on it. The holes made by the laser beam are called pits, interpreted as bit 0 and unburned areas are called lands interpreted as bit 1. Lower power laser beam is used to retrieve the data.

• DVD (Digital Versatile Dipc)
• Blu-ray Disc

iii) Semiconductor storage (Flash memory):
It uses EEPROM chips. It is faster and long lasting.

• USB flash drive: It is also called thumb drive or pen drive. Its capacity varies from 2 GB to 32 GB.
• Flash memory cards: It is used in Camera, Mobile phones, tablets etc to store all types of data.

Question 29.
Write a program to check whether the given number is prime or not.
Answer:
#include<iostream>
using namespace std;
intmain()
{
int n,i;
cout<<“Enter a number”;
cin>>n;
for(i=2;i<=n/2;i++)
{
if(n%i==0)
{ cout<<n<<“ is not a prime no.”;
return 0;
}
cout<<n<<“ is a prime”;
}

Question 30.
a) What is peer-to-peer network?
b) Specify the type of network given below.
ATM network, Cable television network, Network within the school. Network at home using bluetooth, Telephone network, Railway network.
Answer:
a) Peer to peer: in this configuration all the computers have equal priority. That means each computer can function as both a client and a server. There is no dedicated server.

b) PAN – network at home using Bluetooth
LAN – network within the school
MAN – Cable TV network
WAN – Railway, Telephone, Internet, ATM

Plus One Computer Science Previous Year Question Papers and Answers