Heaters and the home network
Answers are for parents and teachers.
1
A heater has R = 20 Ω and I = 6 A. The power in W?
720
2
An electric cooker of 1760 W at 220 V. The current in A?
8
3
A fuse is 10 A (220 V). A 1100 W kettle and an 800 W device run together: total power in W? Will the fuse blow?
1900 W < 2200 W, the fuse will not blow.
4
Write 3 rules of electrical safety at home.
Do not put anything into sockets; do not touch devices with wet hands; tell adults about damaged wires and sockets.
5
Why does a heating coil get hotter than the lead wires?
The coil has a much larger resistance, with the same current, so Q = I²Rt is larger.