The magnitude of an $AC$ voltage used in other countries like America $(USA)$ is $.........$ and its frequency is $.......$.

What is short-circuiting in an electric supply?

What is the role of a fuse used in series with any electrical appliance? Why should a fuse with a defined rating not be replaced by one with a larger rating?

In a household electric circuit,different appliances are connected in parallel to one another. Give two reasons for this. An electrician puts a fuse of rating $5 \, A$ in that part of a domestic electrical circuit in which an electrical heater of rating $1.5 \, kW, 220 \, V$ is operating. What is likely to happen in this case and why? What change,if any,needs to be made?

Which of the following is used in a fire alarm?

Draw an appropriate schematic diagram showing common domestic circuits and discuss the importance of a fuse. Why is it that a burnt-out fuse should be replaced by another fuse of identical rating?