NCERT Class X Science Class: Chapter –13. Magnetic Effects of Electric Current – Part-7

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Question 31:

Describe the working of an AC generator with the help of a labelled circuit diagram. What changes must be made in the arrangement to convert it to a DC generator?

Answer:

Image Electric Motor

Image Electric Motor

Image Electric Motor

The structure of electric generator is similar to that of an electric motor. In case of an electric generator a rectangular armature is placed within the magnetic field of a permanent magnet. The armature is attached to wire and is positioned in way that it can move around an axle. When the armature moves within the magnetic field an electric current is induced.

The direction of induced current changes, when the armature crosses the halfway mark of its rotation. Thus, the direction of current changes once in every rotation. Due to this, the electric generator usually produces alternate current, i.e. AC.

To convert an AC generator into a DC generator, a split ring commutator is used. This helps in producing direct current.

Question 32:

Draw an appropriate schematic diagram showing common domestic circuits and discuss the importance of fuse. Why is it that a burnt out fuse should be replaced by another fuse of identical rating?

Answer:

Image circuit prevents damage

Image Circuit Prevents Damage

Image circuit prevents damage

A fuse in a circuit prevents damage to the appliances and the circuit due to overloading. Otherwise, the appliances or the circuit may be damaged.When current in the circuit exceeds the value of fuse rating, the fuse wire burns due to overloading. This causes a gap in the circuit and the current stops flowing in the circuit.This is done due to the reason so that the circuit or the appliances to be connected in the circuit continue functioning without any damage in future.

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