Question

copper wire has a resistivity of 1.7*10^-8 ohms, a wire of diameter 1.5mm and a length of 25m is connected across a pdf 50v.Calculate the energy expended in one minute?

Answer 1

Explanation:

Given:

d=0.5mm=0.5×10

−3

m

r=

2

d

=

2

0.5×10

−3

=0.25×10

−3

m

A=Πr

2

=3.14×(0.25×10

−3

)

2

ρ=1.6×10

−8

Ωm

R=10Ω

WeknowR=

A

ρl

orl=

ρ

RA

=

1.6×10

−8

10×3.14×(0.25)

2

×10

−6

=1.226×10

2

=122.6m