What is the usual current rating of the fuse wire in the line to feed (a) Lights and fans? (b) Appliances of 2 kW or more power ?

What is the usual colour of the insulation of : (a) live wire, (b) neural wire, and (c) earth wire ?

Suppose your parents have constructed a two room house and you want that in the living room there should be a provision of one electric bulb one electric fan, a refrigerator and a plug point for appliances of power up to 2 kilowatt. Draw a circuit diagram showing electric fuse and earthing as safety devices.

A 10 m long nichrome wire having 80 Omega resistance has current carrying capacity of 5 A. This wire can be cut into equal parts and equal parts can be connected in series or parallel. What is the maximum power which can be obtain as heat by the wire from a 200 V mains supply? (in kW)

A vaccum cleaner draws a current of 2 A from the mains supply (a) What is the appropriate value of the fuse to be fitted in its circuit ? (b) What will happen if a 13 A fuse in fitted in its circuit ?

An electric kettle rated as 1200 W at 220 V and a toaster rated at 1000 W at 220 V are both connected in parallel to a source of 220 V. If the fuse connected to the source blows when the current exceeds. 9.0 A, can both appliances be used at the same time ? Illustrate your answer with calculations.

(a) How does the wire in the filament of a light bulb behave differently to the other wires in the circuit when the current flows? (b) What property of the filament wire accounts for this difference?

(a) On what factor does the current rating of a pole fuse depend? (b) Does the function of a fuse-wire depend on it length?