Electro magnetic induction practice · Mixed difficulty

Assertion : The coils in the resistance boxes are made by doubling the wire.
Reason :When two coils are wound on each other, the mutual inductance is zero.

A rectangular, a square, a circular and an elliptical loop, all in the $\left( {x - y} \right)$ plane, are moving out of a uniform magnetic field with a constant velocity $\vec V = v\vec i$ . The magnetic field is directed along the negative $z$-axis direction. The induced $emf$, during the passage of these loops, out of the field region, will not remain constant for

Lenz’s law is a corollary of the law of conservation of

Two pure inductors each of self inductance $\text{L}$ are connected in series, the net inductance is

Three solenoid coils of same dimension, same number of turns and same number of layers of winding are taken. Coil $\mathrm{1}$ with inductance ${L_1}$ was wound using a $\mathrm{Mn}$ wire of resistance $\mathrm{11}\,\,\mathrm{\Omega }{m^{ - 1}}$;Coil $\mathrm{2}$ with inductance ${L_2}$ was wound using the similar wire but the direction of winding was reversed in each layer; Coil $\mathrm{3}$ with inductance ${L_3}$ was wound using a superconducting wire. The self-inductance of the Coils ${L_1},{L_2},{L_3}$ are

A square current carrying loop is changed to a circular loop in time $t_1$. Then

S-I: Induced e.m.f. tries to keep the energy conserved.

S-II: An e.m.f can be induced between the two ends of a straight copper wire when it is moved through a uniform magnetic field.

A small coil is introduced between the poles of an electromagnet so that its axis coincides with the magnetic field direction. The number of turns is n and the cross sectional area of the coil is $A$. When the coil turns through ${180^0}$ about its diameter, the charge flowing through the coil is $Q$. The total resistance of the circuit is $R$. What is the magnitude of the magnetic induction

A coil having 500 square loop each of side 10 cm is placed normal to a magnetic flux which increases at the rate of 1.0 tesla/second. The induced e.m.f in volts is

A coil having an inductance of $0.5\,\,H$ carries a current which is uniformly varying from zero to $\mathrm{10}\,\,\mathrm{ampere}$ in $\mathrm{2}\,\,\mathrm{second}$. The e.m.f. (in volts) generated in the coil is

A coil having an area $2{\mkern 1mu} \,{\mkern 1mu} {m^2}$ is placed in a magnetic field which changes from $1\,\,wb/{m^2}$ to $4\,\,wb/{m^2}$ in an interval of 2 second. The average e.m.f. induced in the coil will be

If the current through a coil changes from $1 \mathrm{~A}$ to $3 \mathrm{~A}$ in $0.02 \mathrm{~s}$ to produce an emf of $6 \mathrm{~V}$, then the self-inductance of the coil is

A boat is moving due east in a region where the earth’s magnetic field is $5.0 \times {10^{ - 5}}\,\,\mathrm{N}{\mathrm{A}^{ - 1}}{\mathrm{m}^{ - 1}}$ due north and horizontal. The boat carries a vertical aerial $1{\mkern 1mu} \mathrm{2}\,\mathrm{m}$ long. If the speed of the boat is $\mathrm{1}\mathrm{.50}\,\,\mathrm{m}{\mathrm{s}^{ - 1}}$, the magnitude of the induced emf in the wire of aerial is

As a result of change in the magnetic flux linked to the closed loop shown in the fig, an e.m.f. V volt is induced in the loop. The work done (joule) in taking a charge $\mathrm{Q}$ coulomb once along the loop is

Two identical coaxial circular loops carry a current $i$ each circulating in the same direction. As the loops are moved away from each other

An inductor is connected to a battery through a switch induced emf is $\mathrm{e}_1$ when the switch is pressed and $\mathrm{e}_2$ when the switch is opened. Then

Assertion: Acceleration of a magnet falling through a long solenoid decreases.
Reason: The induced current produced in a circuit always flow in such direction that it opposes the change to the cause that produced it.

Assertion (A) : Electric field produced by a variable magnetic field can't exert a force on a charged particle.

Reason (R) : This electric field is non-conservative in nature.

A rod of $10 \mathrm{~cm}$ length is moving perpendicular to uniform magnetic field of intensity $5 \times {10}^{-4} \mathrm{~Wb} / \mathrm{m}^2$. If the acceleration of the rod is $5 \mathrm{~m} / \mathrm{s}^2$ then rate of increase of induced emf is ____

A wheel with 30 metallic spokes each of $0.7 \mathrm{~m}$ long is rotated with a speed of $120 \mathrm{~rev} / \mathrm{min}$, in a plane normal to the horizontal component of earth's magnetic field $\mathrm{H_E}$ at a place. If $\mathrm{H_E}=0.8\,G$ at the place, what is the induced emf between the axle and the rim of the wheel?
Given $1 \mathrm{~G}=10^{-4} \mathrm{~T}$

Principle of working of AC generator is

The horizontal component of the earth’s magnetic field at a place is $3 \times {10^{ - 4}}\,\,T$ and the dip is $\mathrm{\theta } = {\tan ^{ - 1}}\left( {4/3} \right).$ A metal rod of length 0.25 m placed in the north-south position is moved at a constant speed of 10m/s towards the east. The emf induced in the rod will be…….mv

In a transformer, the coefficient of mutual inductance between the primary and the secondary coil is 0.2 henry. When the current changes by 5 ampere/second in the primary, the induced e.m.f. in the secondary will be:

An e.m.f. of $5\,\,volt$ is produced by a self inductance, when the current changes at a steady rate from $3\,\,A$ to $2\,\,A$ in $\mathrm{1\, milli\,second}$. The value of self inductance is

Assertion: Electric force and magnetic force are jointly called electromagnetic force.
Reason: Electric and magnetic effects are inseparable.

If '$\mathrm{N}$' is the number of turns in a circular coil, the value of its self inductance varies as

Electromotive force is the force which is able to maintain a constant

An emf of $0.5 \mathrm{~V}$ is developed in the secondary coil, when current in primary coil changes from $5.0 \mathrm{~A}$ to $2.0 \mathrm{~A}$ in 300 millisecond. Calculate the mutual inductance of the two coils.

When you walk through a metal detector carrying a metal object in your pocket, it raises an alarm. This phenomenon works on:

The net magnetic flux through any closed surface, kept in a magnetic field is