Question

At 25oC,the resistance of a given wire of length 1m and diameter 0.5m.m is
25ohm .what is the resistivity of the material of the wire at that temperature?

Answer 1

Answer:

ANSWER

R=26 Ω

l=1m

d−0.3mm

r=

2

d

=

2

0.3×10

−3

=0.15×10

−3

m

A=πr

2

=3.14×(0.15×10

−3

)

2

=0.071×10

−6

m

2

R=

A

ρL

or ρ=

l

RA

=

1

26×0.071×10

−6

=1.84×10

−6

Ωm