Question

A wire ABCDEF (with each side of length L) bent as shown in Fig. and carrying a current I is placed in a uniform magnetic field B parallel to the positive y - direction. What is the magnitude and direction of the force experienced by the wire?

• A. BIL along positive z-direction
• B. $\frac{B{I}^2}{L}$ along positive z-direction
• C. BIL along negative z-direction
• D. $\frac{BL}{I}$ along negative z-direction

Answer 1

The correct option is A

BIL along positive z-direction

Wires AB and EF experience no forces since currents in them are parallel to the magnetic field. The forces on BC and DE are equal in magnitude but are directed in opposite directions. Hence their resultant is zero. Only force acting is on CD. Hence the correct choice is (a).