Question

A conducting loop carrying a current I is placed in a uniform magnetic field pointing into the plane of the paper as shown (fig). The loop will have a tendency to

• A. contract
• B. expand
• C. move toward +ve x-axis
• D. move toward -ve x-axis

Answer 1

Answer: (B)

expand

Consider a small element of length dl of the loop. It will experience a force idlB outward. There will be a diametrically opposite element dl which will experience an opposite force.
Hence, the loop will have a tendency to expand.