The period of oscillations of a magnet is 2 sec. When it is remagnetised so that the pole strength is 4 times its period will be

Options

A. `4 sec`
B. `2 sec`
C. `1 sec`
D. `1//2 sec`

Answer

C

Explanation

`T prop 1/sqrt(M) implies T prop 1/sqrt(m)`,
If `mrarr 4` times then `Trarr 1/2` times
i.e., `T^(')=T/2=2/2=1 sec`