Question

A wire of given material having length l and area of cross section A has a resistance of 4 ohms. What would be the resistance of anoter wire of the same material having lengyh 1/2 and the area of cross section 2A

Answer 1

Answer:

1 ohm

Explanation:

(hey! You haven't mentioned whether the new length is just 1/2 or 1/2 of L, so I've assumed that the new length is L/2)

Resistance= ρL/A = 4 ohms-------(i)

according to the question,

$l_{2}$= L/2

$A_{2}$= 2A

resistivity will remain same as material is same

so the new resistance is = ρ$\frac{L/2}{2A}$ = ρL/4A

=> $\frac{(i)}{4}$ = 4/4= 1Ω