Give reason for the following:
(i) Electric bulbs are usually filled with chemically inactive gases like nitrogen and argon.
(ii) Copper and aluminium wires are usually employed for electricity transmission.
(iii) Fuse wire is placed in series with the device.

Explanation

(i) Electric bulbs are usually filled with chemically inactive gases like nitrogen and argon because these gases do not react with the hot tungsten filament and hence prolong the life of filament of the electric bulb.
(ii) Copper and aluminium wires are usually employed for electricity transmission because copper and aluminium have very low resistivity and thus they are very good conductors of electricity.
(iii) Fuse wire is placed in series with the device because when large current passes through the circuit the fuse wire gets heated up and melts and whole circuit breaks and the device is protected from the damage.