Describe with the help of a diagram an instrument which can be used to detect a charged body. [5 MARKS]
Explanation: 3 Marks
Diagram: 2 Marks
1. Take an empty bottle. Take a piece of cardboard slightly bigger in size than the mouth of the bottle. Pierce a hole in it so that a metal paper clip could be inserted.
2. Open out paper clip as shown. Cut two strips of aluminium foil about 4 cm × 1 cm each. Hang them on the paper clip as shown. Insert the paper clip in the cardboard lid so that it is perpendicular to it.
3. Take the charged object and touch it with the end of the paper clip. The aluminium foil strips receive the same charge from the charged object through the paper clip. The strips carrying similar charges repel each other and they become wide open. Such a device can be used to test whether an object is carrying charge or not. This device is known as electroscope.