A student investigated the variation of current I with potential difference V for a semiconductor diode in forward bias. The following data were recorded.

V (V)	0	0.1	0.2	0.3	0.4	0.5	0.6	0.7
I (mA)	0	0	0	0	5	20	70	220

(i) Draw a circuit diagram for this experiment with the diode in forward bias.

(ii) Draw a suitable graph to show the relationship between I and V for a diode in forward bias.

(iii) Is Ohm’s law obeyed for this diode? Justify your answer.

Ohm’s law states that current is directly proportional to voltage. That would create a straight line through the origin, which is clearly not the graph shape here. Therefore, the diode is not obeying Ohm’s law.

The student then investigated the variation of current I with potential difference V for a diode in reverse bias. Several adjustments were made to the circuit.

(iv) Draw a circuit diagram for this experiment with the diode in reverse bias.

(v) Sketch a graph to show the relationship between I and V for a diode in reverse bias.