Electromagnetic Induction

A conducting bar of length L is free to slide on two parallel conducting rails as shown in the figure. Two resistors R1 and R2 are connected across the ends of the rails. There is a uniform magnetic field $\stackrel{}{}$ pointing into the page. An external agent pulls the bar to the left at a constant speed v.

The correct statement about the directions of induced currents I1 and I2 flowing through R1 and R2 respectively is:

The magnetic field in a region is given by B = B₀(x/a)k. A square loop of side d is placed with its edges along the x and y axes. The loop is moved with a constant velocity v = v₀i. The emf induced in the loop is:

In the given figure the magnetic flux through the loop increases according to the relation φB(t) = 10t² + 20t, where φB is in milliwebers and t is in seconds. The magnitude of current through R = 2Ω resistor at t = 5s is _____ mA.

A circular conducting coil of radius 1 m being heated by the change of magnetic field B passing perpendicular to the plane in which the coil is laid. The resistance of the coil is 2μΩ. The magnetic field is slowly switched off such that its magnitude changes in time as B = (4/π) * 10?³ T [1 - ( t/100 )]. The energy dissipated by the coil before the magnetic field is switched off completely is E = _______ mJ.

An inductor of 10 mH is connected to a 20 V battery through a resistor of 10 kΩ and a switch. After a long time, when maximum current is set up in the circuit, the current is switched off. The current in the circuit after 1 µs is x/100 mA. Then x is equal to _______. (Take e?¹ = 0.37)

An aeroplane, with its wings spread 10m, is flying at a speed of 180 km/h in a horizontal direction. The total intensity of earth's field at that part is 2.5 * 10^-4Wb/m² and the angle of dip is 60°. The emf induced between the tips of the plane wings will be………….

A coil of inductance 2H having negligible resistance is connected to a source of supply whose voltage is given by V = 3t volt. (where t is in second). If the voltage is applied when t = 0, the energy stored in the coil after 4s is…………… J.

A sheet is placed on a horizontal surface in front of a strong magnetic pole. A force is needed to:

A. hold the sheet there if it is magnetic.

B. hold the sheet there if it is non-magnetic.

C. move the sheet away from the pole with uniform velocity if it is conducting.

D. move the sheet away from the pole with uniform velocity if it is both, non-conducting and non-polar.

Choose the correct statement(s) from the options given below:

A tightly wound 100 turns coil of radius 10 cm carries a current of 7 A . The magnitude of the magnetic field at the centre of the coil is (Take permeability of free space as $4\pi *10^{-7}SI$  units):

In the above diagram, a strong bar magnet is moving towards solenoid-2 from solenoid-1. The direction of induced current in solenoid-1 and that in solenoid-2, respectively, are through the directions: