Science [ 2 Marks Questions ]

The substances which allow electric current to flow through them easily are called conductors. Examples: Impure water and metals.
The substances which do not allow the electric current to flow through them are called insulators. Examples: Rubber and wood.

Silver is a good conductor. But it is a costly metal. So it is not preferred for making electric wire.

Yes, the bulb will glow:
1. Take a lemon. Squeeze it without breaking its skin. The squeezing action releases the juice inside the lemon needed as the battery works.
2. Use a nail to make one hole in one end of the lemon and push a copper wire into that hole.
3. Then, push the nail into the other end.
4. Connect a bulb with one of the terminals with the copper wire and the other terminals with the nail, as shown in the figure.
5. Now the lemon generates a small amount of electricity and the bulb glows.

Two or more cells are combined together to make a battery or collection of cells.

The thermal energy generated by burning coal is used to produced steam. The steam thus produced is used to rotate the turbine. While the turbine rotates, the coil of wire kept between the electromagnet rotates. Due to electromagnetic induction, electricity is produced.

1. Connect the positive terminal of one cell with the negative terminal of another cell.
2. The bulb will glow.

A key, connecting wires, dry cell or battery, and electric bulb.