In previous classes, you had learnt about electric current, battery,
electric circuit and its components.
• What do you mean by electric current?
• Which type of charge (positive or negative) flows through an electric
wire when it is connected in an electric circuit?
• Is there any evidence for the motion of charge in daily life situations?
In class VIII you learned about lightning. Lightning is an electric
discharge between two clouds or between cloud and earth. This electric
discharge through air appears to us as an electric spark or lightning.
Lightning is a live example which provides evidence for the motion of
charge in the atmosphere.
• Does motion of charge always lead to electric current?
Let us see.
Situation 1: Take a bulb, a battery, a switch and few insulated copper
wires. Connect the ends of the copper wires to the terminals of the battery
through the bulb and switch. Now switch on the circuit and observe the
bulb.
• What do you notice?
the battery from the circuit and connect the
remaining components to make a complete circuit. Again switch on the
circuit and observe the bulb. Does the bulb glow?