Question

If the daimeter of awire is halved then its resistence becomes

Answer 1

Answer:

1/16 times the initial resistance

Explanation:

as resistance is inversly proportional to area of the wire

R1-initial resistance=(resistivity × lenght)/a1.......1

a1=area initially=π x r²

R2=(resistivity x lenght of wire)/a2................2

a2=area after changed=π x (r/4)²=pi x r²/16 (∵, d/2=r/4)

dividing 1 and 2

R1/R2=a1/a2=1/16