Question

A Copper wire has diameter 05 M M and resistivity
of 16 x 10-8 πM
what should be the length of time
wire fornatic its resistance 10π​

Answer 1

Answer:

Given, diameter, d=0.5 mm

resistivity, ρ=1.6×10-⁸Ωm

Resistance, R=10 Ω

Let the length of wire be l.

A=πd²/4. R= pl/a = pl/rd²4. =>l= Rrd²/4p. l=10×3.14×(0.5×10-³)²4×1.6×10-⁸ l=122m. . R∝1/d²