ELECTRICAL RESISTANCE

3 marks · Normal

An electric heater draws a current of 2.5 A when a voltage of 60 V is applied across it.

(a)

State the equation that relates voltage, current and resistance.

[1 mark]

(b)

Calculate the resistance of the heater. Include units.

[2 marks]

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) V=I \times R

(b) 24 \; \Omega ohm

Common mistakes: using incorrect formulae; wrong units

Show mark scheme and worked solution

Marking points

B1 (a) · 1 mark · States correct formula V = I x R or rearrangement.

M1 (b) · 1 mark · Substitutes correct values into formula. (follow-through)

A1 (b) · 1 mark · Correct calculation and unit: 24 Ω.

Worked solution

(a) The equation is:

(b) Rearranging for resistance: