Electrical power and energyIB MYP Physics: Mind map

Exam questions on Electrical power and energy

1. A café owner in Istanbul buys a new electric kettle. The label on the base states that it is designed for the 230 V mains supply. While testing it, she finds that the kettle draws a steady current of 8.0 A when switched on.
   The kettle has a power of 1840 W. Calculate the energy it transfers in 3.0 minutes.2 marks
2. A family in Cairo has a 2.0 kW air conditioner. They run it for 6.0 hours every day. Their electricity supplier charges 10 cents for each kilowatt-hour (kWh) of energy.
   Calculate the cost of running the air conditioner for 30 days.2 marks
3. A student investigates how efficiently an electric heater warms water. She connects a 12 V heater, which carries a current of 5.0 A, to a beaker of water and switches it on for 5.0 minutes. She then measures how much thermal energy the water has gained.
   Calculate the power of the heater and the electrical energy transferred to it in 5.0 minutes.3 marks