Question

A current carrying conducting square frame of side l carrying current I is placed in a uniform transverse magnetic field $\overrightarrow{B}$ as shown in the figure. Choose the incorrect statement.

• A. Magnitude of force on the frame is $4IBl$
• B. Magnitude of torque on the frame $I{l}^{2}B$
• C. Torque on the frame is zero
• D. Both $\left(1\right)$ and $\left(2\right)$

Answer 1

The correct option is A Magnitude of force on the frame is $4IBl$

Magnetic force due to a current carrying conductor is $F=BIlsin\theta$

Since the ring is forming a square loop where curreent flowing in each sides is same ie; I.

Therefore, Magnetic force on the frame due to magnetic field is, $F=\left(4l\right)BIsin{90}^0$

$F=4lBI$