Question

two metallic wires A and B of the same material are connected in parallel wire A has length L and radius R wires B has length 3L and radius 3R compute the ratio of the total resistance of parallel combination and the resistance of wire A​

Answer 1

Answer:

Explanation:

Wire A

Length = l.

Radius =r.

Area =pie r2.

R1= rho x l /pie r2.

Wire B.

Length = 3l

Radius = 2r.

Area = pie 9r2.

R2= rho x 3l/pie 9r2=rho x l /pie x 3r2.

total resistance.

1/Rp= 1/R1+1/R2.= pie r2/rho x l+2 pie r2/ rho x l.=4 pie r2/rho x l.

Rp= rho x l/ 4 pie x r2.

ratio = Rp/ R1= rho /4 pie r2 divided by rho x l / pie x r2.

Rp / R1= 1 : 4

Hope it helps you.