1. Which of these is the correct description of mains electricity?

• A). 50V a.c.
• B). 230V a.c.
• C). 50V d.c.
• D). 230V d.c.

2. What is the name of the extra safety wire found in some mains plugs?

• A). live
• B). earth
• C). neutral
• D). return

3. Which of these gives the correct colours of the three wires?

4. The safety device that limits the current flow in a plug is the

• A). fuse
• B). cable grip
• C). earth wire
• D). insulation

5. Where should the earth wire be connected inside a metal toaster?

• A). power supply
• B). heating element
• C). metal casing
• D). neutral wire junction

6. Which part of the mains plug should be connected to the fuse?

• A). live wire
• B). earth wire
• C). neutral wire
• D). placed between live and neutral wires

7. This table shows electrical properties of parts of the plug. Which answer is correct?

8. This hair dryer has a case made of plastic. It only needs 2 wires for safe use. Devices like this are called

• A). neutral devices
• B). safety checked
• C). current controlled
• D). double insulated

9. Which one of these is the symbol for devices like this with plastic cases, only needing 2 wires?

A.	B.	C.	D.
	-//-

10. When a current passes through a resistance wire it gets hot. Which of these appliances does NOT use this effect?

• A). Toaster
• B). Microwave
• C). Hairdryer
• D). Kettle

11. Which of these is the correct formula for electrical power?

• A). P = IV
• B). V = IR
• C). V = PI
• D). P = V/I

The table below gives some appliances and some information about their electical properties. Fill in the missing gaps and choose the best fuse for the toaster.