Practical Electricity：练习题

A household electric oven is rated at \(240\text{ V}, 3000\text{ W}\). Which of the following fuse ratings is most suitable for this appliance?

Why is a fuse connected to the live wire in a domestic electrical appliance?

The cost of electricity is \(\$0.20\) per \(\text{kW h}\). How much does it cost to operate a \(2\text{ kW}\) air conditioner for \(8\) hours?

An electrical appliance with a constant power rating is used for \(30\text{ minutes}\) and consumes exactly \(1.5\text{ kWh}\) of electrical energy. What is the power rating of this appliance?

Which component in a mains circuit should always be connected to the live wire to ensure safety when the appliance is switched off or if a fault occurs?

An electric kettle is rated at \( 2.4 \text{ kW} \). Calculate the energy consumed, in \( \text{kWh} \), if it is used for \( 15 \text{ minutes} \).