Mutual Induction

Q.

Changing the current in one coil induces EMF in another one, this phenomenon is called

1. Self induction

2. Self conduction

3. Mutual induction

4. Mutual conduction

Q. Two similar circular loops of radius R, are lying concentrically with their planes at right angles to each other .The currents flowing in them are (I) and (I\sqrt3) respectively .The magnetic field at yhe centre of the coil is

Q.

What is an electric motor ? State its principle.

Q.

In mutual induction, there is ___.

1. an induced magnetic field in one coil due to a direct current in the neighbouring coil

2. an induced current in one coil due to an alternating current in the neighbouring coil

3. an induced capacitance in one coil due to an alternating current in the neighbouring coil

4. strong magnetic field induced in the primary coil due to a direct current in the secondary coil

Q.

On what factors, does the magnitude of the emf induced in a circuit depends?

Q. Changing current in a coil produces EMF in the same coil. This phenomenon is known as

1. Mutual Induction
2. Self-Induction
3. Induced EMF
4. Induced Current

Q.

Two coils are placed close to each other. Then the mutual inductance of the pair of coils depends upon ____

1. the conductivity of the two coils.

2. the rates at which currents are changing in the two coils.

3. the relative position and orientation of the two coils.

4. the materials of the wires of the coils.

Q. { Two wires }AO and }OC carry equal }} currents i as shown in figure. One end } of both the wires extends to infinity. }{ Angle AOC is }α . The magnitude of }}{ magnetic field at point }P on the bisector }} of these two wires at a distance r from } point O is

Q.

Which of the following is the working principle of transformer?

1. Self induction

2. Reverse voltage

3. Reverse current

4. Mutual induction

Q.

The coil to which we give current for the production of the magnetic field is the primary coil and the coil in which induced emf is generated is known as?

1. Secondary Coil

2. Tertiary Coil

3. None of these

4. Primary Coil

Q. Changing current in one coil induces EMF in another, this phenomenon is called

1. EMF
2. Induced EMF
3. Mutual Induction
4. Self-Induction

Q. Which among the following energy conversion takes place in an electric motor?

1. Heat energy $\to$ Mechanical energy
2. Electrical energy $\to$ Mechanical energy
3. Electrical energy $\to$ Light energy
4. Mechanical energy $\to$ Electrical energy

Q. For a given lenght L of a wire carrying current I how many cicular turns woud produce maximum magnetic moment of what value

Q. Which energy conversion takes place in electric generators?

Q. In generator, electricity is produced due to the phenomenon of electromagnetic induction.

1. True
2. False

Q. In generator, electricity is produced due to the phenomenon of electromagnetic induction.

1. True
2. False

Q. 20.The supply voltage to room is 120 V. Theresistance of the lead wires is 6 Ω . A 60 W bulbis already switched on. What is the decreaseof voltage across the bulb, when a 240 Wheater is switched on in parallel to the bulb:(2) 2.9 Volt(4 10.40 Volt(1) Zero Volt(3) 13.3 Volt

Q.

Two circular coils can be arranged in any of the three situations shown in the figure. Their mutual inductance will be ____

1. maximum in situation (C).

2. maximum in situation (B).

3. maximum in situation (A).

4. the same in all situations.

Q. Choose the correct pairs.

1. Inductance
2. Capacitance
3. Resistance
4. farad ($F$)
5. ohm ($\Omega$)
6. henry ($H$)

Q.

In the figure given below, a coil is placed between two permanent magnets and it is rotated with the help of an axle, on which two rings R1 and R2 are internally attached. B1 and B2 represents metallic brushes. G represents galvanometer.

The current flowing through the circuit reverses direction periodically, such a current is called alternating current. The current can be made direct by ___.

1. replacing the north pole of the permanent magnet by a south pole

2. changing the position of the Galvanometer to the stationary part of the circuit

3. replacing the metallic brushes by fibre brushes

4. changing the commutator to split ring type

Q. two long parallel current carring wire I1=30A& I2=60A caring current in opposite direction distance between them is 2m.another wire carring current of 10A opposite to i2is place between then net magnetic field per unit length on 3ed wire is

Q. In an experiment to know the intensity of magnetic field around a current carrying coil, why is the coil kept in the North South Direction.

Q. Question 4
Choose the correct option.
A rectangular coil of copper wires is rotated in a magnetic field. The direction of the induced current changes once in each
(a) two revolutions
(b) one revolution
(c) half revolution
(d) one-fourth revolution

Q. In generator, electricity is produced due to the phenomenon of electromagnetic induction.

1. True
2. False

Q. In generator, electricity is produced due to the phenomenon of electromagnetic induction.

1. False
2. True

Q. The number of turns in the primary and the secondary coils of a transformer are 1000 and 3000 respectively. If the primary of the coil is connected to 80 volt ac, then what is the potential difference per turn of the secondary coil ?

1. 0.24 V
2. 240 V
3. 0.08 V
4. 24 V

Q. The induced emf produced when a magnet is inserted into a coil does not depend upon:

1. The number of turns in the coil
2. The resistance of the coil
3. All the above
4. The speed of approach of the magnet

Q. The direction of current in the coil at one end of an electromagnet is clockwise. This end of the electromagnet is.

1. north pole
2. south pole
3. east pole
4. west pole

Q. Two identical loops , one of copper and the other of aluminium, are rotated with the same angular speed in the same magnetic field. Compare
(i) The induced emf
(ii) the current produced in the two coils justify your answer.