Question

A hoop and a solid cylinder of same cylinder of same mass and radius are made of a permanent magnetic material with their magnetic moment parallel to their magnetic moment parallel to their respective axes. But the magnetic moment of hoop is twice of solid cylinder. they are placed in a uniform magnetic moments make a small angle with the field. If the oscillation periods of hoop and cylinder are $T_{h}and{T}_c$ respectively, then:

• A. $T_h=0.5T_c$
• B. $T_h=2T_c$
• C. $T_h=1.5T_c$
• D. $T_h=T_c$

Answer 1

Answer: (D)

$T_h=T_c$

$T=2\pi \sqrt{\frac{I}{\mu B}}$
$T_h=2\pi \sqrt{\frac{m{R}^2}{\left(2\mu \right)B}}$
$T_C=2\pi \sqrt{\frac{1/2m{R}^2}{\mu B}}$