Faraday's Law of Induction

Q.

If I keep the north pole of a bar magnet facing a conducting loop and move it towards the loop, I find a current flowing through it, let's say in the clockwise direction. If I want a current to flow in the counter clockwise direction using the same bar magnet, I should :

1. Keep the north pole facing the loop and move it away

2. Both B and C

3. Move the north pole towards the loop in the same way but faster

4. Keep the south pole facing the loop and move it towards the loop

Q. A circular flexible current loop of radius R carrying current i is placed in an inward magnetic field B. If we spin the loop clockwise with angular speed ω, then tension in string (Assume the mass of the loop is m)

Q.

If I keep the north pole of a bar magnet facing a conducting loop and move it towards the loop, I find a current flowing through it, let's say in the clockwise direction. If I want a current to flow in the counter-clockwise direction using the same bar magnet, I should

1. Keep the south pole facing the loop and move it towards the loop.

2. Both (b) and (c).

3. Move the north pole towards the loop in the same way but faster.

4. Keep the north pole facing the loop and move it away.

Q. When there is a moving magnet in the vicinity of a coil, there will be current flowing through the coil.

1. False
2. True

Q.

If I keep the north pole of a bar magnet facing a conducting loop and move it towards the loop, I find a current flowing through it, let's say in the clockwise direction. If I want a current to flow in the counter clockwise direction using the same bar magnet, I should :

1. Move the north pole towards the loop in the same way but faster

2. Keep the south pole facing the loop and move it towards the loop

3. Keep the north pole facing the loop and move it away

4. Both B and C

Q. When the magnet and the coil are moved in the same plane, in the same direction, with the same speed, no current will be induced.

1. False
2. True

Q.

The phenomenon of electromagnetic induction is:

1. The process of charging a body.

2. The process of generating magnetic field due to a current passing through a coil.

3. Producing induced current in a coil due to change in flux linked with the coil.

4. The process of rotating a coil of an electric motor.

Q. The changes in the magnetic field lines around a circuit causes an electromotive force (emf) to be induced in it.

1. False
2. True

Q. An electric current is induced in a circuit when:

1. A magnet is brought close to a wire.
2. A magnet is kept close to a wire.
3. A magnet is taken away from a wire.
4. A magnet is kept far from a wire.

Q. When a magnet is brought close to a wire, the magnetic field around the wire ___.

1. changes.
2. goes to infinite.
3. remains constant.
4. becomes zero.

Q.

Change in the number of magnetic field lines pasing through a coil induces an emf in the coil.

1. True

2. False

Q. The principle of electromagnetic induction was given by .

1. Oersted
2. Faraday
3. Ampere

Q. Faraday's law of electromagnetic induction states about how an electromotive force (emf) is induced in a closed circuit.

1. False
2. True

Q.

State the two laws of electromagnetic induction.

Q. Figure shows a metallic square frame of edge a in a vertical plane. A uniform magnetic field B exists in the space in a direction perpendicular to the plane of the figure. Two boys pull the opposite corners of the square to deform it into a rhombus. They start pulling the corners at t = 0 and displace the corners at a uniform speed u. (a) Find the induced emf in the frame at the instant when the angles at these corners reduce to 60°. (b) Find the induced current in the frame at this instant if the total resistance of the frame is R. (c) Find the total charge which flows through a side of the frame by the time the square is deformed into a straight line.
Figure

Q. A uniform magnetic field B exists in a cylindrical region, shown dotted in figure. The magnetic field increases at a constant rate . Consider a circle of radius r coaxial with the cylindrical region. (a) Find the magnitude of the electric field E at a point on the circumference of the circle. (b) Consider a point P on the side of the square circumscribing the circle. Show that the component of the induced electric field at P along ba is the same as the magnitude found in part (a)
Figure