Electromagnetic...

A thin circular ring of area $$A$$ is held perpendicular to a uniform magnetic field of induction $$B$$. A small cut is made in the ring and a galvanometer is connected across the ends such that the total resistance of the circuit is $$R$$. When the ring is suddenly squeezed to zero area, the charge flowing through the galvanometer

A thin wire is bent from a square loop $$ABCD$$. A battery of e.m.f. $$2V$$ is connected between the points $$A$$ and $$C$$. The magnetic induction due to the current in the loop at centre $$O$$ will-

A small linear segment of an electric circuit is lying on $$x-$$axis extending from $$x=-\dfrac {a}{2}$$ to $$x=\dfrac {a}{2}$$ and a current $$i$$ is following in it. The magnetic induction due to the segment at a point $$x=a$$ will be?

A uniform with resistance $$20\Omega/m$$ in bent in the form of a circle as shown in the figure. If the equivalent resistance b/w P & Q is 13.8 Omega, then the length of the shown selection is 

In the figure shown a square loop $$PQRS$$ of side $$'a'$$ and resistance $$'r'$$ is placed in near an infinitely long wire carrying a constant current $$I$$. The sides $$PQ$$ and $$RS$$ are parallel to the wire. The wire and the loop are in the same plane. The loop is rotated by $$180^{\circ}$$ about an axis parallel to the long wire and passing through the mid point of the side $$QR$$ and $$PS$$. The total amount of charge which passes through any point of the loop during rotation is

A conducting rod of length $$2l$$ is rotating with constant angular speed $$\omega$$ about its perpendicular bisector. A uniform magnetic field $$\vec {B}$$ exists parallel to the axis of rotation. The emf induced between two ends of the rod is

A conductor having two semicircular section are made to translate in the uniform magnetic filed $$B$$ and $$2B$$ as shown with a constant velocity $$v$$ then the induced emf developed across the ends of conductor is 

Th circular arc (in $$x-y$$plane) shown in figure rotates (about $$z-axis$$) with a constant angular velocity $$\omega $$. Time in a cycle for which there will be induced $$emf$$ in the loop is:

A conducting rod of  length $$0.5 m $$ rotates about a horizontal axis passing through one of its ends and perpendicular to its length with angular velocity of $$4 rad/s$$. A uniform magnetic field of $$2.0T$$ exists parallel to the axis of rotation. The emf developed across the ends of the conductor will be 

A metal rod of resistance $$20 \omega$$ is fixed along a diameter of conducting ring of radius 0.1 m and lies in x-y plane. There is a magnetic field $$\overrightarrow B = (50T) \hat{k}.$$ The ring rotates with an angular velocity $$\omega = 20 rad/s$$ about its axis. An external resistance of $$10\Omega$$ is connected across the center of the ring and rim. The current through external resistance is