Question

A toroid of mean radius 'a' cross section radius 'r' and total number of turns N it carries a current 'i' The torque experienced by the toroid if a uniform magnetic field of strength B is applied is:

• A. Zero
• B. $BiN\pi r^2$
• C. $BiN\pi a^2$
• D. depends on the direction of magnetic field

Answer 1

The correct option is A Zero

Given :A toroid of mean radius 'a' cross section radius 'r' and total number of turns N it carries a current 'i' The torque experienced by the toroid if a uniform magnetic field of strength B is applied is:

Solution :

In toroid magnetic field is present only inside the body with no magnetic field outside the body hence magnetic moment M=0 so it will not be affected by any other magnetic field hence torque experienced by toroid will be 0.

The correct opt: A