Question

Two wires of same material have their lengths in the ratio of 2 : 3 and radii 8 : 9. Equal value of p.d. of applied between their ends (separately). Calculate the ratio of current through them.

Answer 1

Answer:

9:16

Explanation:

We know that the Resistance of a same wire is proportional to (l/A) .

where L = Length of wire,

A = Area of cross section

And, Area is proportional to d^2 ,

where 'd' is diameter of wire.

Resistance is proportional to

We have,

Ratio of their length = 1:2

Ratio of diameters = 2:3

Ratio of Area of cross- section = 2^2:3^2 = 4:9

Ratio of resistance :

9:16

Since, current in series circuit is same.

Ratio of Potential difference across wires :

R(1) : R(2) = 9:16

Hence, Required Ratio is 9:16

Hope it helps you mate ..........