Question

Several wires of varying thickness are all made of the same material and all have the same length. If the wires are arranged in order of decreasing thickness, what can be said about the ordering of their resistance?A. The wires will be arranged in order of increasing resistance.B. The wires will be arranged in order of decreasing resistance.C. The ordering of the resistances can not be determined because the resistivity is not given.D. The ordering of the resistances can not be determined because the length is not given.

Answer 1

Answer:

Option A is correct.

The wires will be arranged in order of increasing resistance.

Explanation:

The resistance of a wire is given by

r = (ρl)/A

where r = resistance of the wire

ρ = resistivity of the wire

L = length of the wire

A = cross sectional area of the wire

Provided all the other parameters are constant, resistance is inversely proportional to cross sectional area

r ∝ (1/A)

And the the cross sectional Area of the wire increases with increase in thickness & decreases with thickness

So, decreasing thickness ----> Decreasing Cross sectional Area ----> Increasing resistance.