In which wire in an A.C. housing circuit is the switch introduced to operate the lights?

If fuses of 250 m A, 500 mA, 1 A, 5 A and 10 A were available, which one would be the most suitable for protecting an amplifier rated at 240 V, 180 W?

When does an electric short circuit occur?

In household circuits, is a fuse wire connected in series or in parallel?

Usually three insulated wires of different colours are used in an electrical appliance. Name the three colours.