Question

The resistance of a piece of wire of length is 20m and cross-sectional area 8×10^-6m^2 is ? [Resistivity of wire =5×10^-7 ohm]

Answer 1

The resistance of a wire is given by the formula:

R = ρL/A

where R is the resistance, ρ is the resistivity, L is the length of the wire, and A is the cross-sectional area.

Substituting the given values, we get:

R = (5×10^-7 ohm) x (20m) / (8×10^-6m^2)
R = 1.25 ohm

Therefore, the resistance of the wire is 1.25 ohm.