Electro magnetic induction practice · Medium

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.

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

If coil is open then $L$ and $R$ become

When the number of turns and the length of the solenoid are doubled keeping the area of cross-section same, the inductance

Whenever a magnet is moved either towards or away from a conducting coil, an emf is induced, the magnitude of which is independent of

When a wire loop is rotated in a magnetic field, the direction of induced e.m.f. changes one in each

Induction furnace uses ……… to produce heat.

The electromagnetic force induced in coil is given by

The direction of induced current in a conductor when moved in a magnetic field can be determined by

A bar magnet is released from rest along the axis of a very long vertical copper tube. After some time the magnet will

Self-inductance of two coils is $2 \mathrm{H} \& 8 \mathrm{H}$. If $50 \%$ flux of primary coil is linked with secondary coil, then find coefficient of mutual inductance.

If the current $3.0 \mathrm{~A}$ flowing in the primary coil is made zero in $0.1 \mathrm{~sec}$, the emf induced in the secondary coil is $1.5$ volt. The mutual inductance between the coils is

The magnetic flux $\phi$ (in weber) linked with a coil of resistance $10 \Omega$ varies with time $t$ (in second) as $\phi=8 {t}^2-4 t+1$. The current induced in the coil at $t=0.1 \mathrm{~sec}$ is

In a region at a distance $r$ from $z$-axis, magnetic field $\vec{B}=B_0 r t \hat{k}$ is present where $B_0$ is constant and $t$ is time. Then the magnitude of induced electric field at a distance $r$ from $z$-axis is given by

The magnetic flux linked with a coil of resistance $2\,\,\,\Omega$ at any instant is given by $\phi = 5{t^2} - 10t + 50\,\,\,{\text{weber}}.$ The emf in the coil at $t = 2\,\,\,{\text{seconds}}$ is

A square loop of wire, side length $\mathrm{10}\,\,\mathrm{cm}$ is placed at angle of $\mathrm{45}^\circ$ with a magnetic field that changes uniformly from $\mathrm{0}\mathrm{.1 T}$ to zero in $\mathrm{0}\mathrm{.7 s}$. The induced current in the loop (its resistance is $\mathrm{1}\,\,\mathrm{\Omega })$ is

For a current carrying inductor, emf associated is $20 \mathrm{~m} \mathrm{V}$. Now, current through it changes from $6 \mathrm{~A}$ to $2 \mathrm{~A}$ in $2 \mathrm{~s}$. The coefficient of mutual inductance is

Assertion: Eddy currents are produced in any metallic conductor when magnetic flux is changed around it.

Reason: Electric potential determines the flow of charge.

If magnetic monopoles exists then Gauss's law in magnetism can be written as