(a(i))[2]
Complete Fig. 3.2 so that it shows the useful movement of energy from the Sun to the battery.
(a(ii))[1]
Explain why the battery needs a long time to charge when the day is cloudy.
(b)[3]
Once the cell phone has been used, its outer surface is warm. After it is switched off, it cools. Name and describe the three processes by which thermal energy is transferred away as the cell phone cools.
(c)[3]
The battery takes 4.5 hours to charge with an average current of $300\,\text{mA}$. Calculate the quantity of charge that enters the battery. State the unit of your answer.