Q. A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) pushed into the coil (ii) withdrawn from inside the coil (iii) held stationary inside the coil.

Q. Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by strong magnetic field to your right side. What is the direction of magnetic field?

Q.

State whether following statements are True or False:

(a) An electric motor converts mechanical energy into electrical energy

(b) An electric generator works on principle of electromagnetic induction

(c) The field at the center of a long circular coil carrying current will be parallel straight lines

(d) A wire with a green insulation is usually the live wire of an electric supply

Q. Which of the following correctly describes the magnetic field near a long straight wire?

1. the field consists of straight lines perpendicular to the wire
2. the field consists of straight line parallel to the wire
3. the field consists of concentric circles centered on the wire
4. the field consists of radial lines originating from wire

Q. Draw a labeled diagram of an electric motor. Explain its principle and working. What is the function of split ring in a electric motor.

Q. When is the force experienced by a current-carrying conductor placed in a magnetic field largest?

Q. Two circular coils A and B are placed close to each other . If the current in the coil A is changed, some current be induced in the coil B. Give reason.

Q. What is the function of an earth wire? Why is it necessary to earth metallic appliances?

Q. Explain the underlying principle and working of electric generator by drawing a labelled diagram. What is the function of brushes?

Q. Name some devices in which electric motors are used.

Q. The device used for producing electric current is called a :

1. generator.
2. motor.
3. galvanometer.
4. ammeter.

Q. At the time of short circuit, the current in the circuit

1. does not change
2. reduces substantially
3. increases heavily
4. vary continuously

Q.

State the rule to determine the direction of a

(I) magnetic field produced around a straight conductor-carrying current

(ii) force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it, and

(iii) current induced in a coil due to its rotation in a magnetic field.

Q. When does an electric short circuit occur?

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. the process of rotating a coil of an electric motor
4. producing induced current in a coil due to relative motion between a magnet and the coil

Q. How does a solenoid behave like a magnet? Can you determine the north and south poles of a current-carrying solenoid with the help of a bar magnet? Explain.