Lenz's Law, Eddy Currents & Induced Electric Field

Two similar circular loops carry equal currents in the same direction. On moving coils further apart, the electric current will

A bar magnet falls from a height through a metal pipe. Its acceleration will be ($g$ = acceleration due to gravity)

A bar magnet falls from a height 'h' through a metal pipe, its acceleration after coming out of pipe is

Spherical insulating ball and a spherical metallic ball of same size and mass are dropped from the same height. Choose the correct statement out of the following {Assume negligible air friction}

Three identical coils $C_1, C_2$ and $C_3$ are closely placed such that they share a common axis. $C_2$ is exactly midway. $C_1$ carries current $I$ in anti-clockwise direction while $C_3$ carries current $I$ in clockwise direction. An induced current flows through $C_2$ will be in clockwise direction when

Out of the following which law obeys the law of conservation of energy?

A copper ring having a cut such as not to form a complete loop is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring as shown in figure. The acceleration of the falling magnet is ( $g =$ acceleration due to gravity)

A copper ring is held horizontally and a bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet while it is passing through the ring is

Figure shows the north pole of a magnet moving away from a thick conducting loop containing a capacitor. The excess positive charge will arrive on

A conducting ring of certain resistance is falling towards a current carrying straight long conductor. The ring and conductor are in the same plane. Then

The coil and magnet are moved in the same direction with same speed (V). The induced e.m.f. is

Match List I with List II

Choose the correct answer from the options given below:

Match List I with List II

Choose the correct answer from the options given below:

A hollow metal pipe is held vertically and bar magnet is dropped through it with its length along the axis of the pipe. The acceleration of the falling magnet is ( $g =$ acceleration due to gravity)

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

Spherical insulating ball and a spherical metallic ball of same size and mass are dropped from the same height. Choose the correct statement out of the following

{Assume negligible air friction}

Certain galvanometers have a fixed core made of non magnetic metallic material. The function of this metallic material is

The magnet is moved towards the coil with speed '$V$'. The induced e.m.f. in the coil is '$e$'. The magnet and the coil move away from one another each moving with speed '$V$'. The induced e.m.f. in the coil is

Given below are two statements: one is labelled as Assertion $\mathbf{A}$ and the other is labelled as Reason $\mathbf{R}$

Assertion A: A bar magnet dropped through a metallic cylindrical pipe takes more time to come down compared to a non-magnetic bar with same geometry and mass.

Reason R: For the magnetic bar, Eddy currents are produced in the metallic pipe which oppose the motion of the magnetic bar.

In the light of the above statements, choose the correct answer from the options given below

Two conducting wire loops are concentric and lie in the same plane. The current in the outer loop is clockwise and increasing with time. The induced current in the inner loop is

Eddy currents are produced when

A coil is placed in a magnetic field $\vec{B}$as shown below:

A current is induced in the coil because $\vec{B}$is:

A bar magnet is passing through a conducting loop of radius R with velocity $v$. The radius of the bar magnet is such that it just passes through the loop. The induced e.m.f. in the loop can be represented by the approximate curve:

Metal rings $P$ and $Q$ are lying in the same plane, where current I is increasing steadily. The induced current in metal rings is shown correctly in figure

A small bar magnet is moved through a coil at constant speed from one end to the other. Which of the following series of observations will be seen on the galvanometer G attached across the coil?

Three positions shown describe:

(a) the magnet's entry

(b) magnet is completely inside and

(c) magnet's exit.

A long solenoid of radius R carries a time (t) - dependent current

I(t)=I0t(1 - t). A ring of radius 2R is placed coaxially near its middle. During the time interval 0 $\le$ t $\le$ 1, the induced current (IR) and the induced EMF(VR) in the ring change as:

In which of the following devices, the eddy current effect is not used?

A very long solenoid of radius R is carrying current I(t) = kte–at(k > 0), as a function of time (t $\ge$ 0). counter clockwise current is taken to be positive. A circular conducting coil of radius 2R is placed in the equatorial plane of the solenoid and concentric with the solenoid. The current induced in the outer coil is correctly depicted, as a function of time, by :-

A uniform magnetic field is restricted within a region of radius r. The magnetic field changes with time at a rate $\frac{d\vec{B}}{dt}$. Loop 1 of radius R > r encloses the region r and loop 2 of radius R is outside the region of magnetic field as shown in the figure. Then the e.m.f. generated is

An electron moves on a straight line path XY as shown. The abcd is a coil adjacent to the path of electron. What will be the direction of current, if any, induced in the coil?

Figure shows a circular area of radius R where a uniform magnetic field $\vec{B}$is going into the plane of paper and increasing in magnitude at a constant rate. In that case, which of the following graphs, drawn schematically, correctly shows the variation of the induced electric field E(r)?

A coil is suspended in a uniform magnetic field, with the plane of the coil parallel to the magnetic lines of force. When a current is passed through the coil it starts oscillating; It is very difficult to stop. But if an aluminium plate is placed near to the coil, it stops. This is due to:

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

A metal ring is held horizontally and bar magnet is dropped through the ring with its length along the axis of the ring. The acceleration of the falling magnet is

Faraday's laws are consequence of conservation of

Eddy currents are produced when