Domestic Electric Circuits

a) In the circuit below, in case of an overload, will the fuse protect the electric oven from damage? Justify your answer.

b) If the oven has a rating of $13 \mathrm{A}$, what should be the minimum rating of the fuse?

Electrical devices often have an ampere marking to indicate the strength of electric current required for it to work.

Which wire should be connected to the negative terminal of a socket?

Which circuit shows the correct and safe positions for the fuse and the switch?

A fuse can be used to protect an electrical circuit. Explain why a $13 \mathrm{A}$ fuse is suitable for a circuit in which the greatest current is usually $10 \mathrm{A}$.

An electric heater calibrated $1.5 \mathrm{kW}$, $230 \mathrm{V}$ is connected to a household branch circuit having $5 \mathrm{A}$ fuse wire and is, made to work. What will happen?

Draw a schematic labelled diagram of a domestic wiring circuit which includes (i) a main fuse (ii) a power meter (iii) one light point (iv) a power plug.

Which part of an electrical appliance is earthed and why?

Four electric appliances are connected to the mains supply fitted with a fuse of $10 \mathrm{A}$. The ratings of the appliances are $40 \mathrm{W}, 220 \mathrm{V}; 600 \mathrm{W}, 220 \mathrm{V}; 900 \mathrm{W}, 220 \mathrm{V}; 2000 \mathrm{W}, 220 \mathrm{V}$. When all the appliances are working simultaneously, what do you expect to happen and why? To prevent the blowing up of fuse, what combinations of appliances can you use?

What will happen if an electric fuse is fitted into the neutral wire instead of the live wire? What will happen if it is fitted into the earth wire?

Match the items in Column I to those in Column II.

Note: Option (c) changed from potential difference between neutral and earth wires in a domestic circuit in volts to works on heating effect of current.

Draw the diagram of ring system in household circuits.

In the given figure, the lightning arrangement is protected by $3A$ fuse. What would happen, if all the lamps were replaced by $200 \mathrm{W}$ lamps and they all are switch on?

In the given figure, the lightning arrangement is protected by $3 \mathrm{A}$ fuse. How many units of energy will the system consume, if all the lamps are on for $20$ hours?

In the given figure, the lightning arrangement is protected by $3 \mathrm{A}$ fuse. What current flows through the fuse when all the lamps are switched on?

Distinguish between the term "overloading" and "short circuiting" as used in domestic circuits.

Draw a schematic labelled diagram of a domestic wiring circuit which includes
(i) a main fuse (ii) a power meter(iii) one light point (iv) a power output socket

The various distribution circuits are connected in?

A circuit has a fuse of $5 \mathrm{A}$. Find the maximum number of $100 \mathrm{W}$, $220 \mathrm{V}$ lamps that can be used in the circuit.

An electric oven of $2 \mathrm{k}\mathrm{W}$ power rating is operated in a domestic electric circuit ( $220 \mathrm{V}$) that has a current rating of $5 \mathrm{A}$. What result do you expect? Explain.