Q. A pendulum bob carries a negative charge –$q$ .A positive charge + $q$ is held at the point of support. Then, the time period of the bob is
A) Greater than$\ 2\pi\sqrt{\frac{L}{g}}$
B) Less than $2\pi\sqrt{\frac{L}{g}}$
C) equal to $2\pi\sqrt{\frac{L}{g}}$
D) Equal to $2\pi\sqrt{\frac{2L}{g}}$
Explanation
(c) There is no change in the restoring force as the electrostatic forces are the central forces. Negative and positive charges at the two extremeties of the string affect tension $T$ which does not affect the restoring force
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Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.