Question

a wire of length l and area of cross section A was drawn into wire of double its length by melting it . if its original resistance and resistivity where p and r respectively what will be it's new resistance and new resistivity
​

Answer 1

Explanation:

⇒ Length (l) is doubled & Area of cross section (A) is halved.

l becomes 2l & A becomes

2

A

R=P

A

L

now take l=2l,A=

2

A

R=

A/2

P2l

=4P

A

L

⇒4R

Resistance becomes 4 times

1) Resistivity does not depend on its length 02 Area.

Hence, it does not change.

Answer 2

Answer:

Thanks you so much for free points

Radhe krishna