Question

Two metallic wires are A and B of same material are connected in parallel. Wire A has length'l' and radius 'r'. Wire B has length '2l' and radius '2r'. Calculate the ratio of equivalent resistance in parallel combination and the resistance of wire A

Answer 1

Your answer is in the attachment below

Answer 2

Answer:

given that ,

wire A , L= lm and radius = r and wire B , L= 2l, R= 2r; so we have to find equivalent resistance in parallel combination . So

Explanation:

Resistance = pl/A

1/R= pl/πr square

now, equivalent resistance = 1/R + 1/R1

1/R= 1/pl/πr squre + 1/pl/A

1/R= πrSqure + 3 πr square / pl

1/R= 3πr square / pl

R= pl/ 3πr square/ pl/πr square

Equivalent resistance R= 1/3 = 1:3

(WireB)R= p2l/π(2r) square

R= px/x(2π) square = pl/ 2πr square