Question

A wooden block performs SHM on a frictionless surface with a frequency of $v_0$. The block carries a charge $+Q$ on its surface. If a uniform electric field $\overrightarrow{E}$ is switched on as shown, then the SHM of the block will be of

• A. the same frequency and with a shifted mean position .
• B. a changed frequency and with the same mean position.
• C. the same frequency and with the same mean position.
• D. a changed frequency and with a shifted mean position.

Answer 1

The correct option is A the same frequency and with a shifted mean position .

As frequency of oscillation of wooden block, $f=\frac{1}{2\pi }\sqrt{\frac{K}{m}}$, does not depend on constat external force due to electric field, hence the frequency of oscillation will be the same.
But due to constant external force, the mean position of the wooden block gets shifted.
Hence, option $\left(A\right)$ is correct.