Question

Current i flows through a uniform wire of diameter d when the mean druft velocity is v the same current will flow thorugg a wire of wire diameter d/2 made of the same material if the means drift velocitt of the electrin is

Answer 1

i=neAv Here A=πd²/4 as area of cross section= πr²

Now take i1 as nev(1)πd²/4

and 12 as nev(2)πd²/16

Please note the numbers in brackets are not in calc. they are v1 and v2

Divide 1st equation by second you would get the answer as 4v.

If you have any doubts please ask and please do give me the brainliest answer if you are satisfied with my explanation