Question

A wire of length (l) and cross-section (A) was drawn into a wire of double of its length by melting it. If its
original resistance and resistivity were (p) and (R) respectively, what will be its new resistance and
resistivity?​

Answer 1

Answer:

r will be resistance of wire after melting =

R will before melting = 4R=r,,, resistivity will be 1/4

of its before resistivity

Explanation:

resistivity=let it be. X. (after melting)

we know 4R=r(here r is resistance of wire after melting....)

so. X= r×A/l

so. x=4r×A/l. x is resistivity after melting

X/x=. we get. X=4x

so it will help you

have a good day

thnx.