17 marks
A student sets up an electrical circuit. She draws part of the circuit diagram, as shown in Fig.8.1.
On Fig.8.1, draw the circuit symbols for three devices so that the student can:
(i) measure the total current in the circuit
[1]
(ii) vary the current in the lamp B only
[1]
(iii) measure the potential difference (p.d.) across lamp B.
[2]