Question

A charge Q is distributed uniformly on a non-conducting ring of radius R and mass M. The ring is dropped from rest from a height h and falls to the ground through a non-uniform magnetic field B(r). The plane of the ring remains horizontal during its fall.

Explain qualitatively why the ring rotates as it falls.

Answer 1

The ring rotates as it falls due to the interaction between its rotational motion and the non-uniform magnetic field. This can be explained by the principle of magnetic torque.

Step-by-step explanation:

The ring rotates as it falls due to the interaction between its rotational motion and the non-uniform magnetic field. When the ring is dropped, it experiences a torque due to the non-uniform magnetic field, causing it to start rotating. This can be explained by the principle of magnetic torque, which states that a torque is produced when a current-carrying loop (in this case, the charged ring) is placed in a magnetic field that varies in strength or direction.

Answer 2

Check below for the explanation

Step-by-step explanation:

Since it is stated that the ring is dropped from a height, h, through a non uniform magnetic field, two kinds of force will act on the ring, namely:

• A magnetic force (that is non uniform since the field is non uniform)
• Gravitational force

A certain amount of torque is provided by the non uniform magnetic force on the ring while the force gravity pulls it down. Due to the downward pull by the force of gravity on the ring and the torque acting on it as a result of the non uniform magnetic force, the ring begins to rotate.