Question

A magnet is suspended horizontally in the earth's magnetic field. When it is displaced and released, it oscillates in a horizontal plane with a period T. If a piece of wood of same M.I as the magnet is attached to the magnet is attached to the magnet, the new period of oscillation of the system would be–

• A.
• B.
• C.
• D.

Answer 1

Answer: (D)

Answer 2

T = 2π $\sqrt { \frac { \mathrm { I } } { \mathrm { MB } _ { \mathrm { H } } } }$

T' = 2π $\sqrt { \frac { 2 \mathrm { I } } { \mathrm { MB } _ { \mathrm { H } } } }$ = $\sqrt { 2 }$T