Question

The dipole moment of a magnet is $M$. It's time period of vibration is $T$. If the dipole moment of another magnet is $2M$ with same physical dimensions as the former, the time period of vibration will be

• A. $\frac{T}{2}$
• B. $\frac{T}{\sqrt{2}}$
• C. $T\sqrt{2}$
• D. $2T$

Answer 1

Answer: (B)

$\frac{T}{\sqrt{2}}$

Time period of a dipole $T=2\pi \sqrt{I/\left(\mu M\right)}$

therefore, $T\propto \sqrt{\frac{1}{M}}$

therefore, when $M$ becomes $2M$

then,$T$ becomes $\frac{T}{\sqrt{2}}$.