An electric kettle has an outer casing made of metal. Fig. 7.1 shows the kettle. [Figure 7.1] The heater in the electric kettle is connected to a 230V mains power supply and has a power rating of 2300 W.

1. (a)(i)The kettle is switched on. Calculate the current in the heater.[2]
2. (a)(ii)The manufacturer of the kettle states that the cable for the kettle is safe for currents that are smaller than 15A. The wiring in the mains power supply in the wall is safe for currents that are smaller than 20A. The fuses available for the kettle have the ratings shown. 3A 5A 7A 10A 13A 15A 18A 20A 25A State which of these fuses is the most appropriate. Explain why it is the most appropriate.[2]
3. (b)(i)There are three wires in the cable that connects the kettle to the mains power supply: the earth wire, the live (line) wire, the neutral wire. The wires are all correctly connected. State the name of the wire that the fuse is connected into. Explain why the fuse is connected into this wire.[2]
4. (b)(ii)The insulation on the live wire is damaged so that the wire is exposed. Explain what happens when the exposed live wire touches the metal outer casing.[2]
5. (c)The kettle is switched on for a total time of 34h during one year. The cost of electricity is $0.32 per kilowatt-hour (kWh). Calculate the cost of using the kettle during the year.[2]

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