devarshi-dt-logo

Question:

A hoop and a solid cylinder of the same mass and radius are made of a permanent magnetic material with their magnetic moments parallel to their respective axes. But the magnetic moment of the hoop is twice that of the solid cylinder. They are placed in a uniform magnetic field, and their magnetic moments make a small angle with the field. If the oscillation periods of the hoop and cylinder are Th and Tc respectively, then:

Th=2Tc

Th=1.5Tc

Th=Tc

Th=0.5Tc

Solution:

T=2π√(Iμ/B)
Th=2π√(mR²(2μ)/B)
Tc=2π√((1/2)mR²μ/B)
Therefore, Th = 2Tc