Question

A wire of given material having length l and area of cross-section A has a resistance of 16 Ω. What would be the resistance of another wire of the same material having length l/2 and area of cross-section 2A? With solution

Answer 1

l = l

A = A

R1 = 4 ohm

R1 = rho  * l/ A

i . e 4 = rho *l / A

in the another wire

l = i/2 * l

A = 2A

R = (rho * 1/2 l) / 2A

  =( rho *l/A ) * 1 / 4

we have rho l / A = 4 ohm

so, 4 * i/ 4

 = 1 ohm