Science Case study (4 Marks)

An electric fuse consists of a metal wire. The wire breaks the electric circuit when the electricity load is too high.

(i) What makes the wire break when the electricity load is too high ?
(a) It is made of metal.
(b) It has a low melting point.
(c) It is a good conductor of heat.
(d) It is a good conductor of electricity.
(ii) Why does the filament of a bulb glow when connected to an electric circuit?
(iii) Which of these can cause a fire in an electric circuit?
Choose Yes or No for the correct response

Can this cause a fire in an electric	Yes or No circuit?
(a) Use of multiple electric fuses	(i) Battery
(b) Flow of a very high electric current	(ii) Electric bulb
(c) Direct touching of two uncovered wires	(iii) Electric bell

(i) What is the function of the switch in the circuit?
(ii) Name the two terminals of a battery.
(iii) Name the alloy used in the filament of bulb. Give its function.
(iv) (a) In the given circuit, name the component that must be hot to work.
(b) Give an example of a device other than a bulb which shows the heating effect of current.