Question 208: Magnetism and Matter

Question

A rigid square loop of side 'a' and carrying
current I
2
is lying on a horizontal surface near
a long current I
1
carrying wire in the same plane
as shown in figure. The net force on the loop
due to wire will be :
![](https://imagex.cdn.examgoal.net/18hoxe66ijwhsjjiz/1e411011-e7c2-45dd-a814-e763aa2cd6b3/e8ea76b0-86c5-11e9-8081-1d558b7f1d26/file-18hoxe66ijwhsjjj0.png)

Accepted Answer

F
3
& F
4
cancel each other.
Force on PQ will be F
1
= I
2
B
1
a
= ${I_2}{{{\mu _0}{I_1}} \over {2\pi a}}a$
= ${{{\mu _0}{I_1}} \over {2\pi a}}a = {{{\mu _0}{I_1}{I_2}} \over {2\pi }}$
Force on RS will be F
2
= I
2
B
2
a
= ${I_2}{{{\mu _0}{I_1}} \over {2\pi 2a}}a = {{{\mu _0}{I_1}{I_2}} \over {4\pi }}$
Net force = F
1
Ã¢ÂÂ F
2
= ${{{\mu _0}{I_1}{I_2}} \over {4\pi }}$ repulsion

Answer

Repulsive and equal to $\mu $
0
I
1
I
2
/4$\pi $

Answer

Attractive and equal to $\mu $
0
I
1
I
2
/3$\pi $

Answer

Repulsive and equal to $\mu $
0
I
1
I
2
/2$\pi $

Answer

Zero

Magnetism and Matter

A rigid square loop of side 'a' and carrying current I 2 is lying on a horizontal surface near a long current I 1 carrying wire in the same plane as shown in figure. The net force on the loop due to wire will be :

Choose the correct answer: