Electromagnetic...

A thin semicircular conducting ring of radius R is falling with its plane vertical in a horizontal magnetic induction B. At the position MNQ, the speed of the ring is v. The potential difference developed across the ring is 

Two circuits, each consisting of a loop of wire are placed in the proximity of one another and one of them is carrying a current. The current is then suddenly stopped. Then

A coil having $$n$$ turns and resistance $$4R$$ $$ \Omega$$. This combination is moved in time $$t$$ seconds from a magnetic field $$W_1$$ weber to $$W_2$$  weber. The induced current in the circuit is : 

A train is moving from south to north with a velocity of $$90$$ km/h. The vertical component of earth's magnetic induction is $$0.4\times { 10 }^{ -4 }\quad Wb/{ m }^{ 2 }.$$ If the distance between the two rails is $$1 m,$$ what is the induced e.m.f. in its axle?

In a given figure an isosceles triangle conducting wire is entering into the region of perpendicular uniform magnetic field $$B_0$$ with constant velocity $$V_0$$. The magnitude of induced emf as a function of time(t) in the wire is(till side is outside the field)

A magnet is brought near a coil in two ways (i) rapidly (ii) slowly. The induced charge will be

A wire of fixed length is wound on a solenoid of length l and radius r. Its self inductance is found to be L.Now if same wire is wound on a solenoid of length $$\dfrac{l}{1}$$ and radius $$\dfrac{r}{2}$$, then self inductance will be 

The coefficient of mutual inductance of two coils is $$6mH$$. If the constant current of $$2A$$  is flowing in one coil , then the induced e.m.f in the second coil will be

An electron originates at a point $$A$$ lying on the axis of a straight solenoid and moves with velocity $$v$$ at an angle $$\alpha$$ to the axis. The magnetic induction of the field is equal to $$BA$$ screen is oriented at right angles to the axis and is located at a distance $$1$$ from the point $$a$$. Find the distance from the axis to the point on the screen into which the electron strikes.

An $$L$$-shaped conductor rod is moving in transverse magnetic field as shown in the figure. Potential difference between ends of the rod is maximum if the rod is moving with velocity :