4.4.1. Uses of electricity
A subsection of Physics, 5054, through 4. Electricity and magnetism
Listing 10 of 84 questions
shows an electric kettle. The body of the kettle is plastic but the outside casing of the heating element is metal. Explain why a fuse is included in the circuit and explain what happens when the fuse blows. Explain why the metal casing of the heating element is connected to earth. The electrical power input to the kettle is 2000 W and the kettle is used for 6 minutes (0.1 hour). Calculate the electrical energy, in J, supplied to the kettle. State clearly the formula that relates power, energy and time. the electrical energy, in kW h, supplied to the kettle. the cost of using the kettle if 1 kW h costs 8 cents. When the kettle is switched off, the water cools down. Explain, in molecular terms, how evaporation causes a loss of energy from the water. plastic water heating element
5054_w05_qp_2
THEORY
2005
Paper 2, Variant 0
View
Questions Discovered
84