1. Extended tier only

Fig. 10.1 shows a transformer.

There are 8000 turns in the primary coil of the transformer. The primary coil is connected to a 240 V mains supply. A 6.0 V lamp connected to the secondary coil operates at full brightness.

(i) Calculate the number of turns in the secondary coil

number of turns = ...........................................................[2]

(ii) The current in the lamp is 2.0A. The transformer operates with 100% efficiency.

Calculate the current in the primary circuit.

current = ...........................................................[2]

(iii) The secondary circuit contains a 6.0 A fuse.

Calculate the maximum number of lamps, identical to the lamp in (ii), that can be connected in parallel in the secondary circuit without blowing the fuse.

 number of lamps = ...........................................................[1]