A hair dryer contains a heating element and a motor that turns a fan. While the hair dryer is in use, the air passing through it becomes warm, the fan blades rotate, warm air is blown onto the hair and the plastic casing becomes warm.
Which energy transfer is wasted?
The kinetic store of the fan blades fills.
The thermal store of the air passing through the hair dryer fills.
The thermal store of the plastic casing fills.
The kinetic store of the air blown onto the hair fills.
105 exam-style questions on Edexcel GCSE Physics 10.3 Electrical energy and power, covering 10.3.1 The heating effect of an electric current, 10.3.2 Reducing energy transfer in wires, 10.3.3 Advantages and disadvantages of the heating effect, 10.3.4 Energy transferred by an electrical circuit, 10.3.5 Electrical power, and 10.3.6 Energy transfers in domestic devices. Each one has a worked solution and a mark scheme showing where the marks go.