Q. The acceleration due to gravity increase by 0.5 % when we go from the equator to the poles. What will be the time period of the pendulum at the equator which beats seconds at the poles?
A) 1.950 s
B) 1.995 s
C) 2.050 s
D) 2.005 s
Explanation
(d) $T = 2\pi\sqrt{\frac{l}{g}}$
$\frac{\mathrm{\Delta}T}{T} = \frac{\mathrm{\Delta}g}{2g}$
or $\mathrm{\Delta}T = - \frac{\mathrm{\Delta}g}{2g} \times T = - \frac{1}{2} \times \left( \frac{- 0.5}{100} \right) \times 2 = + 0.005\ s$
$\therefore$ Time period at equator
$= 2 + 0.005 = 2.005\ s$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.