Question

The length of string of simple pendulum is 101.4 cm and the diameter of bob is 2.64 cm. What is the effective length of simple pendulum up to required significant figures?
1. 102.72 cm
2. 102.7 cm
3. 102.73 cm
4. 102.6 cm

Answer 1

Correct Answer - Option 2 : 102.7 cm

The effective length is given as \({l_{effective}} = l = {l_0} + r\)

\(l = 101.4 + \frac{{2.64}}{2} = 101.4 + 1.32 = 102.72\;cm\)

Since, in addition the least number of decimal figures which occur among the added quantities is to be taken. Hence the number of least decimal figure in the length is 1. Hence,

\(l = 102.7\;cm\)