Question

Two parallel wires are separated by 1mm, Each is 2m long and carries a current of 3A in the same direction as the other. The forces the two wires exert on each other:

a) Has magnitude 0.0036 N and repels the wires from each other.

b) Has magnitude 0.0036 N and attract the wires to each other.

c) Has magnitude 0.00015 N and repels the wires from each other.

d) Has magnitude 0.00015 N and attract the wires to each other.

Two parallel wires are separated by 1mm, Each is 2m long and carries a current of 3A in the same direction as the other. The forces the two wires exert on each other: a. Has magnitude 0.0036 N and repels the wires from each other. b. Has magnitude 0.0036 N and attract the wires to each other c. Has magnitude 0.00015 N and repels the wires from each other d. Has magnitude 0.00015 N and attract the wires to each other

Answer 1

We know for the same direction of current of two wires the two wires attract each other.

Here d is the distance between two wires and equals to 1 mm =1$\times$10^-3 m.

I₁ is the current in wire 1 and equals to 3 A.

I₂ is the current in wire 2 and equals to 3 A.

L is the length of each wire and equals to 2 m.

Know for 2 parallel wire with carrying current in same direction the net force is

$\therefore \: \: \: F_{net}=\frac{\mu _{0}I_{1}I_{2}L}{2\pi d}$

  $or \: \: \: F_{net}=\frac{4\pi \times 10^{-7}\times 3\times 3\times 2}{2\pi \times 1\times 10^{-3}}\: \: \: N$

  $\therefore \: \: \: F_{net}=0.0036\: \: \: N$

$\therefore$ The forces the two wires exert on each other (b) has magnitude 0.0036 N and attract the wire each other.