# The length of string of a simple pendulum as measured by a meter scale was found to be $98.2 \;cm$ The diameter of the bob was measured by a vernier caliper and it was found to be $3.62\;cm$ The time for 10 oscillations was found to be 21.2 s What is the effective length of the pendulum

$\begin{array}{1 1}(A)\;24\;cm \\(B)\;100\;cm \\(C)\;9.8 \;cm \\(D)\;2 \;cm \end{array}$

Effective length = length of string + radius of bob.
$\qquad= 98.2 \;cm +\large\frac{1}{2}$$(3.64) cm$
$\qquad= 100 \;cm$
Hence B is the correct answer.
answered Jul 11, 2014 by