Question

If the resistance of conducting wire P is four times resistance of conducting wire Q then the ratio of cross sectional areas of wire is

Answer 1

let the resistance of conducting wire Q =R

then resistance of conducting wire P= 4R

let area of cross section of wire P and Q be Ap and Aq

as we know that Rα 1/A

Rp/RQ= Aq/Ap

4R/R=Aq/Ap

∴Ap/Aq= 1/4

∴ The ratio of their area of cross section is 1:4