Question

The time period of a freely suspended magnetic needle does not depend upon

• A. length of the magnet
• B. pole strength
• C. horizontal component of earth's magnetic field
• D. length of the suspension fibre

Answer 1

Answer: (D)

length of the suspension fibre

Answer 2

The time period of oscillation of a bar magnet suspended in air is given by $T =2 \pi \sqrt{\frac{ I }{ MB _{ H }}}$ It depends on , Moment of Inertia( depends on length and breadth of the magnet), magnetic moment and earth's horizontal magnetic field.