The acceleration due to gravity at a place changes from `9.8 m//s^(2) " to " 9.5 m//s^(2)`. Then the length of the second's pendulum changes by

Options

A. 0.3 m
B. 3 cm
C. 0.3 cm
D. 6 cm

Answer

B

Explanation

`T=2pi sqrt((L)/(g)) therefore 4=(4pi^(2)L)/(g) therefore L=(g)/(pi^(2))`
`therefore L_(1)-L_(2)=(g_(1)-g_(2))/(pi^(2))=0.03m= 3cm`