All the distribution circuits for domestic purposes are parallel connections.

$(a)$ Draw a schematic labelled diagram of a domestic wiring circuit which includes $(i)$ a main fuse,$(ii)$ a power meter,$(iii)$ one light point,and $(iv)$ a power plug.
$(b)$ Why is it necessary to connect an earth wire to electric appliances having metallic covers?

What is a fuse? How does it function?

$(a)$ When do we state that an electrical appliance is earthed? Mention the function of the earth wire in electric lines. Why is it necessary to earth electric appliances having a metallic body?
$(b)$ Explain what is short-circuiting and overloading in an electric supply.

An alternating electric current has a frequency of $50 \, Hz$. How many times does it change its direction in one second? Give reason for your answer.

Name three colours used and names of the wires used in household wiring.