Since volume is same in both cases => l'A'=l×A => 3l×A'=l×A =>A' =A/3
R'=ρ×l'/A' = (ρ×3l)/ (A/3) =>R'=9ρl/A = 9R
resistance increases by 9 times
Regular exam updates, QnA, Predictors, College Applications & E-books now on your Mobile