Question

Two long, straight wires are fixed parallel to one another a distance do apart. The wires carry equal constant currents 1, in the same direction. The attractive magnetic force per unit length between them if f = F/L. What is the force per unit length between the wires if their separation is 2d, and each carries current 210? 10 da lo A. f/4 B. f/2 C. 3f/2 D. 2f

Answer 1

The option (B) is correct.

Step-by-step explanation:

The magnetic force between the two current carrying wires is given by

`F =(\mu o)/(4\pi)* (2 I I')/(r)`

where, I and I' be the currents in the wires and r is the distance between the two wires.

Here, we observe that the force between the wires is inversely proportional to the distance between them.

So, when the distance is doubled , let the new force is F'.

`(F')/(F)=(r)/(r')\\\\(F')/(F)=(d)/(2d)\\\\F'=(F)/(2)`

So, option (B) is correct.