A circular current loop is placed in an external magnetic field.How is the torque related to the radius of the loop?
A)directly proportional to radius
B)inversely proportional to radius
C)directly proportional to radius squared
D)inversely proportional to radius squared

Question

Quizplus · Accepted Answer

The torque on a current loop in an external magnetic field is given by the formula T = NIAB sinθ, where N is the number of turns in the loop, I is the current, A is the area of the loop, B is the magnetic field, and θ is the angle between the magnetic field and the normal to the plane of the loop. Since the area of a circular loop is πr^2, we can write T = NI(πr^2)Bsinθ. Therefore, torque is directly proportional to the radius squared.

A Circular Current Loop Is Placed in an External Magnetic