Fig. 6.1 shows part of a mains circuit that includes three lamps and a heater. rating = 5 A live heating circuit fuse lighting circuit fuse heater neutral lamp type P lamp type P lamp type Q [Figure 6.1]

1. (a)The mains voltage is 230 V, and the power of the heater is 2000 W. There is a 5A fuse in the lighting circuit. Four fuses of different ratings are available for use in the heating circuit as shown in the list. Underline the most suitable fuse value for the heating circuit fuse, and explain your choice. Your answer must include a calculation. available fuses: 5 A 8 A 13 A 30 A calculation explanation[3]
2. (b)Describe what happens to a fuse when the current is too large.[1]
3. (c)(i)Table 6.1 shows the current in lamps of type P and type Q when connected to the mains supply. Table 6.1 lamp type current/A P 0.26 Q 0.43 Calculate the current in the lighting circuit fuse when all three lamps are switched on. current = ....................................................A[1]
4. (c)(ii)The rating for the lighting circuit fuse in Fig. 6.1 is 5A. The lamp of type Q is removed from the circuit. Calculate the maximum number of additional lamps of type P that can now be connected in parallel to the lighting circuit. number of additional lamps = ....................................................[1]
5. (d)In some houses the lighting circuit is protected by a trip switch (circuit breaker) instead of a fuse. State two advantages of using a trip switch rather than a fuse. 1 2[2]

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