EASY
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Two identical metallic square loops L1 and L2 are placed next to each other with their sides parallel on a smooth horizontal table. Loop L1 is fixed and a current which increases as a function of time is passed through it. Then loop L2

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Important Questions on Electromagnetic Induction and Alternating Current

MEDIUM
A coil is placed in a magnetic field B as shown below :
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A current is induced in the coil because B is :
EASY

Two bar magnets A and B, and a non-magnetic bar C, all of same mass and dimensions, are dropped in an identical manner one by one through the center of a copper loop held horizontally (as shown in the figure). The times taken by the bars A, B, and C to reach the ground are tA,tB, and tC, respectively. Which of the following relations is correct?

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EASY

Current from A to B in the straight wire is decreasing. The direction of induced current in circular loop will be :

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EASY
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
EASY
The force on a moving charge in a uniform magnetic field is called-
MEDIUM

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:

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MEDIUM
State Lenz’s law and show that it is in accordance with the law of conservation of energy.
HARD

A square conducting loop is placed near an infinitely long current-carrying wire with one edge parallel to the wire as shown in the figure. If the current in the straight wire is suddenly halved, which of the following statements will be true?
"The loop will "
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EASY

A copper ring having a cut such that it does not 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. Then acceleration of the falling magnet is

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EASY
Out of the following given loops in which loop, the direction of induced current is from acb
MEDIUM

The diagram below shows two circular loops of wire A and B centered on and perpendicular to the x-axis, and oriented with their planes parallel to each other. The y-axis passes vertically through loop A (dashed line). There is a current IB in loop B as shown. Possible actions which we might perform on loop A are

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(i) Move A to the right along x-axis closer to B.
(ii) Move A to the left along x-axis away from B.
(iii) As viewed from above, rotate A clockwise about y-axis.
(iv) As viewed from above, rotate A anticlockwise about y-axis Which of these actions will induce a current in A only in the direction shown.

HARD
A rigid wire loop of square shape having side of length L and resistance R is moving along the x-axis with a constant velocity v0 in the plane of the paper. At t=0, the right edge of the loop enters a region of length 3L where there is a uniform magnetic field B0 into the plane of the paper, as shown in the figure. For sufficiently large v0, the loop eventually crosses the region. Let x be the location of the right edge of the loop. Let v(x), I(x) and F(x) represent the velocity of the loop, current in the loop, and force on the loop, respectively, as a function of x. Counter-clockwise current is taken as positive.

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Which of the following schematic plot(s) is(are) correct ? (Ignore gravity)
MEDIUM
Write Lenz's law of electromagnetic induction. Show that Lenz's law follows the energy conservation law.
EASY

Ajay and his friends went for a walk. There they saw a metallic chain attached to a truck touching the ground. It was also written on the truck, “beware highly inflammable". Ajay explained to his friends that during motion of truck, magnetic lines of the earth are cut by its axle and due to this some e.m.f. will be induced across its ends. This induced charge is discharging to the earth through this metallic chain and explosive materials are safe. 

Answer the following questions on the basis of the above paragraph : Name and state the law which gives direction of induced current. 
 

HARD
A metallic ring of radius a and resistance R is held fixed with its axis along a spatially uniform magnetic field whose magnitude is B0sinωt. Neglect gravity. Then,
HARD
A bar magnet falls with its north pole pointing down through the axis of a copper ring. When viewed from above, the current in the ring will be