Solveeit Logo

Question

Physics Question on Oscillations

A wooden block performs SHM on a frictionless surface with frequency v0v_0. The block carries a charge +Q+Q on its surface. If now a uniform electric field EE is switched-on as shown, then the SHMSHM of the block will be

A

of the same frequency and with shifted mean position

B

of the same frequency and with the same mean position

C

of changed frequency and with shifted mean position

D

of changed frequency and with the same mean position

Answer

of the same frequency and with shifted mean position

Explanation

Solution

Frequency or time period of SHM depends on variable forces.
It does not depend on constant external force. Constant external
force can only change the mean position. For example, in the
given question mean position is at natural length of spring in the
absence of electric field. Whereas in the presence of electric
field mean position will be obtained after a compression of x0x_0 .
Where x0x_0 is given by
Kx0=QEorx0=QEKKx_0 =QE \, \, \, or \, \, x_0 =\frac{QE}{K}
\therefore \, \, \, \, \, Correct answer is (a).