State and explain why electrical sockets and plugs used outside in a garden need to be different from those that can be used safely in a room inside a house.
conditions (outdoors) may be damp / wet
water conducts (electricity) OR clear statement of need for waterproof/outdoor specification (components)
State and explain why fuses and circuit breakers are installed in electrical circuits connected to the mains supply.
protects components / appliances / circuit / wires / user / mains supply prevents electrical supply overheating / fires / electrocution / shocks
excess current / power in circuit/wires OR fuse melts/blows OR circuit breaker opens
An electric iron has a power of 2400 W . The potential difference (p.d.) of the mains supply is 220 V .
Fuse ratings of 3 A,5 A,10 A,13 A and 30 A are available.
State which of these fuse ratings is suitable for use in the iron.
fuse rating
13 A
Four statements about safety when designing electrical products are listed.
1 If the outer casing is a conductor, it should be earthed.
2 If the outer casing is a conductor, it should not be earthed.
3 If the outer casing is an insulator, it should be earthed.
4 If the outer casing is an insulator, it should not be earthed.
Which statements are correct?
1 and 3
1 and 4
2 and 3
2 and 4
B