Question

how will the resistance of a wire change if its diameter is doubled,its length remaining the same​

Answer 1

Answer:

it will be divided by 4

Explanation:

as you know $R=r\frac{d}{A}$

where area is $\frac{x}{y} \pi r^{2} = \frac{\pi D^{2} }{4}$

so if you double the D it will go from this:

$R=r\frac{4d}{\pi D^{2} }$

to this:

$\frac{R}{4} =r\frac{4d}{\pi (2D)^{2} }$

therefore it will be divided by 4

Answer 2

Answer:

R = pl/ A

Here R changes as Diameter doubles then A wil quadruple itself also.

Then

R/R' = A'/A

RA/4A = R'

R' = R/4

I hope it helps .