Question

A current carrying square loop is suspended in a uniform magnetic field acting in the plane of the loop. If \( \vec{F} \) is the force acting on one arm of the loop, then the net force acting on the remaining three arms of the loop is:

• A. \( -3\vec{F} \)
• B. \( 3\vec{F} \)
• C. \( \vec{F} \)
• D. \( -\vec{F} \)
• E. \( -\frac{1}{2}\vec{F} \)

Hint:

The force on each arm of a current-carrying loop in a uniform magnetic field is proportional to the current, the length of the arm, and the magnetic field. For a square loop, the forces on opposite sides cancel out.

Answer 1

The Correct Option is D

Step 1: In a square loop, when a uniform magnetic field acts, the forces on opposite sides are equal in magnitude but opposite in direction. 
The force on each arm is due to the interaction between the magnetic field and the current in the arm. 
Step 2: The force on one arm \( \vec{F} \) is balanced by forces on the other arms. 
Since the magnetic force on each arm is equal in magnitude and opposite in direction, the net force on the remaining three arms will be \( -\vec{F} \), as the forces on the other three arms cancel out.