Question

The length of seconds pendulum is 1 m. The length of simple pendulum at the point of intersection of L-T graph and L-T${}^2$ graph is:

• A. $25$ cm
• B. $50$ cm
• C. $25\sqrt{2}$ cm
• D. $50\sqrt{2}$ cm

Answer 1

The correct option is A $25$ cm

$l=g\times \frac{T^2}{4{\pi }^2}$
For intersection of graphs $T^2$ should be equal to T which happens only when $T=1$
Thus $l=\frac{g}{4{\pi }^2}=\frac{1}{4}m=25cm$