Question

2 wires are of same length, sam3 material have radii r1 and r2. compare their tesistances

Answer 1

R =ρL/A

∵since L1 = L2 =L
A= πr²
A₁= π(R₁)²
A₂ =π(R₂)²
$\frac{R1}{R2}$ = ρ(L1/A1)×ρ(A2/L2)
                                      =(A2/A1)
                                      =(πR₂²)/(πR₁²)
                                      = (R₂²)/(R₁²)