# (a) Name one device which works on the magnetic effect of current.(b) Name one device which works on the phenomenon of electromagnetic induction.(c) Which device converts electric energy into mechanical energy? (d) Describe the principle of working of an electric motor. (e) Explain the principle of working of an electric generator.

(a) Electric Motor is the device which works on the magnetic effect of current.

(b) AC generator is the device which works on the phenomenon of electromagnetic induction.

(c) Electric Motor is the device that converts electrical energy into mechanical energy.

(d) The principle of working of an electric motor is- When a current-carrying wire is moved in a magnetic field, it experiences a magnetic force.

Working of an electric motor can be described by the following steps.

1. Current flows in the loop placed in the magnetic field through a battery.

2. The magnetic field applies force on the loop so that it rotates. Thus, electrical energy gets converted into mechanical energy.

3. But to rotate loop continuously in one direction, the direction of force on wires should keep changing after every half revolution.

4. This is performed by split rings, that facilitate the change in direction of the current.

5. When the direction of the current gets reversed the direction of forces acting on the coil also get reversed. This change in direction of force pushes the coil, and make it move another half turn.

6. In this way, the loop keeps rotating.

(e) The principle of working of an electric generator is- When a straight wire is moved in the magnetic field, induced current flows in it.

Working of an electric generator can be described by the following steps.

1. As the rectangular loop of current-carrying wire is moved in the magnetic field, induced current flows in them due to EMI.

2. As the rectangular loop of current-carrying wire rotate sometimes upwards and sometimes downwards, the direction of current in the circuit get changed.

3. When an arm moves up during half revolution, current flows in one particular direction, and when it moves down in another half revolution, current flows in another direction.

4. In this way, the rectangular loop of the wire keeps rotating.

Updated on: 10-Oct-2022

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