In general, assuming temperature of a conductor is constant, the resistance of a conductor is affected by

1) **length (L) **– [L increases, R increases]

2) **cross-sectional area (A)** – [A increases, R decreases]

3) **resistivity (p) **= [p increases, R increases]

As R is directly proportional to L and p, and is inversely proportional to A,

**R = pL/A**

MCQ questions from Olevel

There are times when using the formula is more appropriate.

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