Page 340 - Computer Science V2.0 Class 11

xxxix. xxxx. xxxxi.

Assertion and Reasoning Based Questions

The following questions are assertion(A) and reasoning(R) based. Mark the correct choice as
a. Both A and R are true and R is the correct explanation of A
b. Both A and R are true and R is not the correct explanation of A
c. A is true but R is false
d. A is false but R is true

Assertion(A): Every loop must have a range() in the header.
Reasoning(R): range() denotes a sequence of numbers.

Case-based Questions

1. Sumita is teaching her younger brother about dividends and divisors. To make him practice the concept, she wants to write
a program in Python that can quickly generate all divisors of a given number. Can you help her in this task?
2. Nusrat has just studied Mersenne numbers. He knows that numbers in the form of 2 1 are called Mersenne numbers. For
n_
example
1
2
2 –1 = 1, 2 –1 = 3, 2 –1 = 7, and so on.
3
He now wants to write a program in Python that displays the first n Mersenne numbers, where n is provided by the user at
execution time. Help him to do that.
NCERT Exercise Solutions

1. What is the difference between else and elif construct of if statement?
Ans.
else elif
else is a part of if statement. The elif is short for else if.
else statement is executed whenever the if statement elif executed block of code whenever one of the condition
is getting false. evaluate true.
Example:
Example:
num = -5
a = 10
if (num > 0):
b = 20
print ("positive number")
if(a < b):
elif (num == 0):
print ("a less than b")
print ("zero")
else:
else:
print ("a is not less than b")
print ("negative number")
326 Touchpad Computer Science (Ver. 2.0)-XI