Alternating current and direct current
3 marks · NormalA fan heater is rated at 1500 W, and operates on 230 V mains supply. Calculate the current in the heater when it is switched on.
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6.52 A (±0.02)
Also accept: 6.5 A; 6.52A; 6.521...
Common mistakes: Using V/I instead of P=IV; Calculation error dividing
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Marking points
M1 · 1 mark · Writes power equation: or rearranges for I.
M2 · 1 mark · Substitutes correct values: P = 1500 W, V = 230 V.
A1 · 1 mark · Correctly evaluates current to 2 decimal places: 6.52 A
Worked solution
Given: W, V.
Rearrange for current:
Substitute values: