Electrical power
4 marks · NormalA table shows data for three different toasters:
| Toaster | Voltage (V) | Current (A) |
|---|---|---|
| X | 230 | 3.0 |
| Y | 230 | 4.0 |
| Z | 230 | 5.0 |
Calculate the power rating for each toaster.
State which toaster would get hottest the quickest and explain why.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
(a) X: 690 W, Y: 920 W, Z: 1150 W · must show Correct substitution for each toaster
(b) Toaster Z, because it has the highest power rating so transfers electrical energy at the fastest rate. · must show Selects Z, Correct explanation
Common mistakes: Choosing smallest current or voltage instead of power
Show mark scheme and worked solution
Marking points
M1 (a) · 1 mark · States/uses correct formula for power.
A1 (a) · 2 marks · Correctly calculates all 3 answers (690 W, 920 W, 1150 W). Award 1 mark for 1–2 correct, 2 marks for all correct.
B1 (b) · 1 mark · Identifies Z with correct reason (most power so more heat per second).
Worked solution
Toaster X: P = 230 × 3.0 = 690 W Toaster Y: P = 230 × 4.0 = 920 W Toaster Z: P = 230 × 5.0 = 1150 W
Toaster Z would get hottest the quickest, as it has the largest power rating.