question_answer

An experiment is performed to obtain the value of acceleration due to gravity g by using a simple pendulum of length L. In this experiment time for 100 oscillations is measured by using a watch of 1 second least count and the value is 90.0 seconds. The length L is measured by using a meter scale of least count 1 mm and the value is 20.0 cm. The error in the determination of g would be:            [JEE ONLINE 09-04-2014]

A)  1.7%   

B)       2.7%

C)  4.4%   

D)       2.27%

Correct Answer: B

Solution :

[b]

According to the question.

or,

or

As we know,

or