Fig. 9.1 shows a gardener cutting damp grass with a high-powered electric mower.
Fig. 9.1
The mower cable has thick wires appropriate for the current of the mower and the correct fuse. This cable is too short, and so the gardener uses an extension cable with thin wires, intended for use with a reading lamp. This cable has no fuse.
Discuss any dangers of the electrical arrangement shown in Fig. 9.1.
[Total: 4]
Two electrical appliances are connected to the mains supply.
The cable connected to one appliance includes an earth wire.
The cable connected to the second appliance does not need an earth wire.
What is a reason for this difference?
One appliance has a metal case, but the other appliance does not.
One appliance is fitted with a fuse, but the other appliance is not.
One appliance is fitted with a switch, but the other appliance is not.
One appliance needs more current than the other appliance.
After some building work in a house, a bare (uninsulated) live wire is left protruding from a wall. What is the greatest hazard?
a fire
a fuse blows
an electric shock
no current flows