Home » CBSE Class 7 Physics Notes- Chapter 4 Electric Current and its  Effects

CBSE Class 7 Physics Notes- Chapter 4 Electric Current and its  Effects

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       CHAPTER 4 ELECTRIC CURRENT AND ITS EFFECTS
 
Every cell has a positive and a negative terminal. A combination of two or more cells such that the positive terminal of one cell is connected with the negative terminal of the next cell is called a battery.
When the switch in a circuit is turned on, current flows. This electric current has some unexpected effects.
 
HEATING EFFECT OF CURRENT
When current passes through a wire it gets heated up which proves that electric current has heating effects.
This is why the wires used in an electric circuit have a high melting point. It ensures that the wires do not melt when they get heated up by the current flowing in them.
The wire used in a fuse however, has a low melting point. If the current in a circuit exceeds the safe limit, the fuse wire melts, thereby breaking the circuit.
 
MAGNETIC EFFECT OF CURRENT
A wire through which current flows exhibits magnetic properties. It behaves like a magnet. This property is used in making electromagnets. An electromagnet is a small device which has a piece of iron with a current carrying coil of insulated wire wrapped around it.

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