(a(i))[3]
Use Fig. 5.1 to explain how the resistance of the diode changes as $V$ rises from zero to $0.8\ \text{V}$.
(a(ii))[2]
Use Fig. 5.1 to find the resistance of the diode when the current is $4.4\ \text{mA}$.
(b(i))[1]
Calculate the current in $R_2$.
(b(ii))[2]
Calculate the resistance of $R_1$.
(b(iii))[2]
Calculate the ratio $\dfrac{\text{power dissipated in the diode}}{\text{power dissipated in }R_2}$.