Which effect of electric current is used in electroplating?

$A$ house is fitted with $5$ tubes each of $40 \, W$. If all the tubes are lighted for $20$ hours and if the cost of electrical unit is ₹ $0.50$,the total cost of electricity consumed is (in ₹)

$(a)$ Give reasons why tungsten is used for making the filament of electric lamps.
$(b)$ Why are the heating elements of electrical appliances made up of an alloy rather than a pure metal?

When is the potential difference between two points said to be $1$ volt?

What are the factors on which the resistance of a conductor depends?

Why is parallel arrangement used in domestic wiring?