Copper and iron wire of same length and diameter are in series and connected acress a battery .The resistance of copper is about one sixth of that of iron If `E_(1)` and `E_(2)` are the electron fields of in the copper and iron wires respectively then which of the following is correct ?

Options

A. `E_(1) lt E_(2)`
B. `E_(1) = E_(2) ne 0`
C. `E_(1) gt E_(2)`
D. `E_(1) = E_(2)= 0`

Answer

a

Explanation

Let `l,A` be the length and area of crossection of each wire in series

Given `rho_("cu") = (1)/(6) rho_(Fe)`
As` V = IR = I(rhol)/(A)`
For copper `V_("Cu") = I rho_("Cu") = (l)/(A) = I(rho_(Fe))/(6) (l)/(A),`
`E_(1) = (V_("Cu"))/(l) = (I rho_(Fe))/(A)`
For iron, `V_(Fe) = I rho_(Fe) (l)/(A) : E_(2) = (V_(Fe))/(l) = (I rho_(Fe))/(A)`
`:. (E_(1))/(E_(2)) = (1)/(6)` Hence `E_(1) lt E_(2)`