Question

There are two wires of the same material and lengths The cross section of the wires are different If the diameter of the fist wire is double that of the second wire then specific resistance of fist wire will be​

Answer 1

Resstance of first wire is R

1

​

=

π(d

1

​

/2)

2

ρl

1

​

​

and resistance of 2nd wire is R

2

​

=

π(d

2

​

/2)

2

ρl

2

​

​

Here, l 1

​

=2l 2

​

,d 1

​

=2d 2

​

Thus,R

1 = π(2d 2 /2)2

ρ(2l 2 )

​

=R 2

​

/2