Edison used a _________ wire coil in a vacuum glass and discovered the first electric bulb in 1879.

The __________ wire serves as a protective conductor , which saves us from electric shocks.

Give a scientific reasons: Tungestm metal is used to make a solenoid type coil in an electric bulb.

Rahul wants to make an electric circuit.He has a bulb, two wires, a safety pin and a piece of copper. He does not have any electric cell or battery.Suddenly he gets some idea. He uses a lemon instead of a battery and makes a circuit.Will the bulb glow?

(a) State Joule's law of heating. (b) an alloy of nickel and chromium is used as the heating element. Why ? (c ) How does a fuse wire protect electrical appliances ?

Quite often, connecting wires carrying currents in opposite directions are twisted together in using electrical appliances. Explain how it avoids unwanted magnetic fields.

Al wires are used as electric cables due to their silvery white colour.

A1 wires are used as electric cables due to their silvery white colour.

An electric bulb is designed to consume 55 W when operated at 110 volts. It is connected to a 220 V, 50 Hz line through a choke coil in series. What should be the inductance of the coil for which the bulb gets correct voltage?