Fig. 3.1 shows a solar-powered charger connected to a cell phone (mobile phone). [Figure 3.1] The battery inside the cell phone is charged by the solar-powered charger.

1. (a)(i)Complete Fig. 3.2 to show the useful transfer of energy from the Sun to the battery. [Figure 3.2][2]
2. (a)(ii)Explain why the battery takes a long time to charge on a cloudy day.[1]
3. (b)After use, the outside surface of the cell phone is warm. When switched off, the cell phone cools down. Name and describe the three processes by which thermal energy is transferred as the cell phone cools down. 1 2 3[3]
4. (c)It takes 4.5 hours to charge the battery with an average current of 300 mA. Calculate the quantity of charge that enters the battery. Give the unit of your answer. charge =[3]

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