(a) Draw, on the axes below, the current/voltage characteristic for a filament lamp. Do not insert any values for current or voltage.

(3 marks)

(b) Explain why the characteristic has the shape you have drawn.

(3 marks)

(c) The current/voltage characteristic of a filament lamp is to be determined using a datalogger, the data then being fed into a computer to give a visual display of the characteristic. Draw the circuit diagram required for such an experiment and state what is varied so as to produce a range of values.

(5 marks)
(Total 11 marks)