If N is the total number of turns in a coil, then the value of self-inductance varies as

Eddy currents are produced in a material when it is?

Lenz's law associated with Faraday's laws of electromagnetic induction are consequence of the conservation of

Self inductances of two uncoupled coils are 40 mH and 90mH. Their mutual inductance is

Magnetic flux through a circuit of resistance 20 $\Omega$ is changed from 20 Wb to 40 Wb in 5 ms. The charge passed through the circuit during this time is

A long straight conductor, carrying current I, is fixed on a smooth plane. A circular loop is placed on the same plane as shown in the figure. If the current I through the wire is increasing, then the loop will move towards:

Two coils have a mutual inductance of 5mH. The current changes in the first coil according to the equation l = l₀cos$\omega$t, where l₀ = 10 A and $\omega$ = 100$\pi$ rad/s. The maximum value of e.m.f. induced in the second coil is?

A circular loop is placed near a current-carrying conductor as shown. If the current in the straight conductor is decreasing, then the direction of the induced current in the loop is

Two rails of a railway track insulated from each other on the ground are connected to a millivoltmeter. The reading of millivoltmeter when the train travels at a speed of 20m/s along the track is (Given: B_v = 0.2$\times$10^-4 Wb/m² and distance between the rails is 1m)

The current through a choke coil increases from zero to 6A in 0.3 seconds and an induced emf of 30 V is produced. The inductance of the coil is?

Self-inductance of primary and secondary of a perfectly coupled coil is 40 mH and 90mH respectively. Coefficient of mutual induction between them is

A conducting square loop of side L and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A constant magnetic field B exists as shown in the figure. Mechanical power required to maintain its uniform velocity is

A conducting disc of radius r rotates about its axis with an angular speed $\omega$ in a uniform magnetic field B perpendicular to the plane of the disc as shown. A resistance R is connected between centre and rim of the disc, then-

A train is moving on a straight horizontal track. Induced emf across the axle is maximum when it moves

A square loop enters a magnetic field with velocity v as shown in the figure. The front edge enters the magnetic field at time t = 0. Which of the following graphs gives the correct variation of emf$\epsilon$ induced in the loop with time t for its constant velocity in the magnetic field? [Take anticlockwise current as negative and vice versa]

A rectangular metal loop ABCD of is passed through the magnetic field with a constant velocity v. Which of the following represents power (P) dissipated vs time (t) graph?

Self-inductance of a solenoid is 5 mH. If the current is decreasing through it at the rate 10⁺³ A/s, then emf induced in the solenoid is

Keeping number of turns constant self inductance L of a solenoid varies with its length l as

A conducting rod AC of length 4l is rotated with angular velocity $\omega$ about a point O in a uniform magnetic field $\overrightarrow{B}$ directed into the plane of the paper. If AO = l and OC = 3l, then the potential difference between A and C, V_A - V_C is

A flexible wire bent in the form of a circle is placed in a uniform magnetic field perpendicular to the plane of the circle. The radius r of the circle changes with time t as shown in the figure. The graph of the magnitude of induced emf $\left|\mathrm{e}\right|$ versus time t in the circle is represented by

A cylindrical space of radius R is filled with a uniform magnetic induction B parallel to the axis of the cylinder. If B changes at a constant rate, the graph showing the variation of the induced electric field with distance r from the axis of the cylinder is

A long conducting wire AH is moved over a conducting triangular wire CDE with a constant v in a uniform magnetic field $\overrightarrow{B}$ directed into the plane of the paper. Resistance per unit length of each wire is r. Then

The figure below shows a square loop of side 0.5 m and resistance 10 $\Omega$. The magnetic field has a magnitude B = 1.0 T. The work done in pulling the loop out of the field slowly and uniformly in 2 seconds is

The wires P₁Q₁ and P₂Q₂ are made to slide on the rails with the same speed 10m/s. If P₁Q₁ moves towards left and P₂Q₂ moves towards the right, then the electric current in the 19$\Omega$ resistor is

The triangular circuit ABC shown in the figure is in a very long solenoid of radius R such that the plane of the triangular circuit is normal to the length of the solenoid. If the magnetic field changes at the rate dB/dt, then the induced emf in the triangular circuit is

If conducting triangle is pulled out with a uniform velocity from the uniform magnetic field, as shown in the figure, then which graph of induced current versus time is possible?

Two circular coils of different radii lie in the same plane with their centres at same point i.e. inner coil is surrounded by a bigger outer coil. If the current in the outer coil is clockwise and increasing with time, then induced current in the inner loop is

A field of 0.2 T acts perpendicular to a coil of area 100cm² with 50 turns. If the coil is removed within 0.1s from the field, then the minimum emf induced in the coil is

If by keeping number of turns per unit length constant, the volume of an air-core inductor is doubled, then its self-inductance will become/remain

Eddy currents are used in