Question

If positively charged pendulum is oscillating in a uniform electric field as shown in figure. Its time period as compared to that when it was uncharged:

• A. will increase
• B. will decrease
• C. will not change
• D. will first increase then decrease

Answer 1

The correct option is A will increase

Time period of oscillating pendulum $T=2\pi \sqrt{\frac{l}{g_{eff}}}$

Where,

$g_{eff}$ is the effective acceleration due to gravity and some other factors.

Here,

$g_{eff}=(g-\frac{F_{electrostatic}}{m})$

As denominator increasing, the time period will increase.