Question

What will be the resistance of a copper wire of
Length 125 m and diameter 3 mm at 20°C? (Given
Pcopper
= 1.62 x 10-8 m).

Answer 1

Answer:

given,

length= 125m

dimeter=3mm

3/1000=3×10-3

theta =20°c

R= PL/A

R=1.62×10-8×125/π/4×(3×10-3)2

R=4× 1.62×10-8×125/3.14×9×10-6

R=500×162×10-8×10-6/314

R=1.59×162×10-2

R=257×10-2

R=257/100

R=2.57ohhm