Page 89 - Science Class 6 Times Publication

The substances which allow current to pass through them are called
conductors. Copper, aluminium, silver, graphite, wet wood, etc are
example of good conductors.

The substances which do not allow current to pass through them are
called insulators. Glass, dry wood, plastic, paper, etc are insulators.
Semi-conductors

The substances which allow only less amount of current to pass through
them are called semi-conductors. For example, silicon, arsenic,
germanium, etc. They behave as conductors at high temperature.

Activity 8.2

Take a dry cell, one torch, bulb and
three pieces of wire. Connect the dry
cell to the bulb as shown in the  gure.
There must be a gap between A and B
as shown in the  gure.

Collect a piece of wire, pencil, cork,
plastic, wood, a piece of stone, etc. Place them in the gap between A

and B turn by turn. What ndings do you get? Record the result in
the following table.

Sn. Materials Bulb glows or not Conductor/Insulator
1. Copper wire Glows Conductor
2. Plastic Does not glow Insulator

3.
4.
5.
6.

Main Points to Remember

1. Electricity is a form of energy which is required to run devices
like computer, refrigerator, television, fan, heater, etc.

2. Cell, dynamo and generator are various sources of electricity.
3. Simple cell consists of zinc plate as negative electrode and
copper plate as positive electrode.

Times' Crucial Science and Environment 85 Book 6