Question

Which of the following factors affect the electrical resistance of a wire?

• A. Length
• B. Cross-sectional area
• C. Colour
• D. Material

Answer 1

Answer: (A), (B), (D)

The correct options are
A Length
B Cross-sectional area
D Material

Resistance of a wire is directly proportional to the length ($l$) of wire and inversely proportional to the area $(A$) of cross-section of wire.
$R=\frac{\rho l}{A}$

where $\rho$, the constant of proportionality, is called electrical resistivity. It depends on the material of the conductor.
Electrical resistance does not depend on the colour of the wire.