A circular loop of variable radius 'r' lying in a perpendicular magnetic field B to its plane. if radius of the loop changes at the rate of `alpha` . then the emf induced at r=2a will be

A square loop of side .a. lying in a perpendicular magnetic field to its plane is changed to a circle. If change occurs in .t. seconds in magnetic field B tesla, the induced emf is

A conducting circular loop is in a perpendicular magnetic field of induction 10^(-2) T If the radius of the loop starts shrinking at a uniform rate of 1 "mm"//s , then the e.m.f. induced in the loop at the instant when its radius is 10 cm will be

the uniform magnetic field perpendicular to the plane of a conducting ring of radius a change at the rate of alpha , then

A uniform circular loop of radius a and resistance R palced perpendicular to a uniform magnetic field B . One half of the loop is rotated about the diameter with angular velocity omega as shown in Fig. Then, the current in the loop is

A uniform circular loop of radius a and resistance R palced perpendicular to a uniform magnetic field B . One half of the loop is rotated about the diameter with angular velocity omega as shown in Fig. Then, the current in the loop is

A circular wire loop of radius r is placed in a region of uniform magnetic field B such that the plane of the loop makes an angle theta with the direction of B. In which of the following conditions, will no emf be induced in the loop?

A circular loop of radius R is kept in a uniform magnetic field pointing perpendicular into the plane of paper. When a current l flows in the loop, the tension produced in the loop is

A conducing circular loop is placed in a uniform magnetic field of indution B tesla with its plane normal to the field. Now, radius of the loop starts shrinking at the rate (dr//dt) . Then the induced e.m.f. at the instant when the radius is r is:

Radius ol a circular luop placed in a perpendicular uniform magnetic field is increasing at a constant rate of r_(o)ms^(1) . If at any instant radius of the loop is r, then emf induced in the loop at that instant will be

A circular flexible loop of wire of radius r carrying a current I is placed in a uniform magnetic field B . If B is doubled, then tension in the loop