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 2I0?
A. f/4
B. f/2
C. 3f/2
D.) 2f

Answer 1

Answer:

Option D

Explanation:

From the question we are told that:

The attractive magnetic force per unit length as

 $f = F/L$

Separation Distance $x=2d$

Generally the equation for  Magnetic force between two current carrying wire is mathematically given by

$\frac{F}{\triangle l}=\frac{\mu_0I_1I_2}{\mu \pi x}$

$\frac{F}{\triangle l }=\frac{I_1I_2}{ x}$

Where

$x=2r$

And

$I_1=I_2=>2I$

Then

$\frac{F}{\triangle l}=>\frac{2*2}{2}*f$

$\frac{F}{\triangle l}=>2f$

Therefore s the force per unit length between the wires if their separation is 2d

$\frac{F}{\triangle l}=>2f$

Option D