Which equation correctly links electric power P, voltage V and current I?
P = V x I
P = I ÷ V
P = V ÷ I
What is the power of a small electric motor if a current of 2 A flows when connected to a 24 V power supply?
0.083 W
12 W
48 W
Use the following electricity meter readings to calculate the cost of electricity used by a school.
Previous reading = 37170 kWh.
Present reading = 41217 kWh.
Units at 14.78 p per kWh.
£2.74
£598.15
£59815
What is the cost of using a 3 kW heater for 9 hours if the price of a unit is 15 p?
1.8 p
£4.05
£405
A microwave has a power rating of 800 W. What size fuse should be used in the plug if the mains voltage is 240 V.
3 A
5 A
13 A