Question

A circular copper-ring of radius r translates in its pl ane with a constant velocity v. A uniform magnetic field B exists in the space in a direction perpendic ular to the planne of the ring. Consider different pairs of diametrically opposite points on the ring.

(a) Between which pair of points is the emf max imum ? What is the value of this maximum emf ?

(b) Between which pair of points is the emf mini mum ? What is the value of this minimum emf ?

Answer 1

(a) The e.m.f is highest between the diameter per pendicular to the velocity because here length per pendicular to velocity is highest.

$E_{max}$ = vB~2R

(b) The length perpendicular to velocity is lowest as the diameter is parallel to the velocity

$E_{max}$ = 0.