Physics

Problem

A wire of length

L

has its radius varying linearly from

r_0

at one end to

2 r_0

at the other end. The wire carries a steady current

I

. Assuming uniform number density

n

of charge carriers and charge

e

, the ratio of the average drift velocity along the length of the wire to the drift velocity at the thinner end is a)

\dfrac{2}{3}

\dfrac{1}{2}

\dfrac{5}{8}

\dfrac{4}{9}