Alternative B
Question 3B
(b) (i) State the four factors that affect the resistance of a wire.
(ii) A 2 Ω resistor is connected in parallel with a resistor of resistance R. If the p.d. across R is 1.2 V and the same amount of current of 0.6 A flows through R and the 2 Ω resistor, determine the value of R.Observation
Part (b) Candidates response was satisfactory.
The expected response:
(b) (i) Factors that affect the resistance of a wire
- length of wire
- cross-sectional area//thickness/diameter of the wire
- nature/material of the wire/resistivity
- temperature
(ii) Determination of the value of R
R = 
R = 
= 2 W