Question

A copper wire has diameter 0.5mmand resistivity of 1.6×10^-8ohmmeter What is the length of tge wire to make a resistance of 10ohm

Answer 1

Answer:

Area of cross-section of the wire, A =π (d/2) 2

Diameter= 0.5 mm = 0.0005 m

Resistance, R = 10 Ω

We know that

∴ length of the wire = 122.72m

If the diameter of the wire is doubled, new diameter=2×0.5=1mm=0.001m

Let new resistance be Rʹ