Shows a circular wire-loop of radius a m carrying a current I, placed in a perpendicualr matgnetic field B. (a) Consider a small part dl of the wire. Find the force on this part of the wire exerted by the magnetic field. Find the force of compression in the wire.

Options

A. `B i a`
B. `2B i a`
C. `5B i a`
D. none

Answer

A

Explanation

To find compression/tension in the ring, find the force on small length of angle `d theta` and red then remove `d theta` from expression

`F_(m) = B i a d theta`
`C = B i a`