. A thin magnetic needle vibrates in the horizontal plane with a period of 4 s

The needle is cut into two halves by a plane normal to magnetic axis of the needle. Then the period of vibration of each half needle is approximately

a. 4 s

b. 2 s

c. 8 s

d. 1 s

Answer ||| (b)

Solution ||| The moment of inertia of needle when it cuts into two halves by a plane normal to magnetic axis of the needle.

Related questions