What type of relationship exists between the length of a wire and the resistance, if all other factors remain the same? A. Resistance is directly related to length. B. Resistance is directly related to the square of the length. C. Resistance is inversely related to the length. D. Resistance is inversely related to the square of the length.

Answer

(A) Resistance is directly related to length.

Explanation

Formula for resistance

R = p (length) / A

where R = resistance

p = resistivity (material of wire)

A = cross sectional area

So it can be seen that resistance depends upon 3 factors that are length of wire, resistivity of wire and the cross sectional area of the wire.

If two of the factors, resistivity and cross sectional area, are kept constant then the resistance is directly proportional to the length of wire.

R ∝ length

This means that the resistance of the wire increases with the increase in length of the wire and decreases with the decrease of length of the wire.