A conductor is placed along z-axis carrying current in z direction in uniform magnetic field directed along y-axis. The magnetic force acting on the conductor is directed along:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → negative x-axis
The magnetic force on a current-carrying conductor is
\( \displaystyle \vec{F} = I\,(\vec{L} \times \vec{B}) \)
The length vector \( \vec{L} \) points along the current, so \( \vec{L} \parallel \hat{k} \), and the field is along \( \hat{\jmath} \).
\( \displaystyle \hat{k} \times \hat{\jmath} = -\hat{\imath} \)
So the force is along the negative x-axis. The force is always perpendicular to both the current and the field, which already rules out the y-axis and the z-axis.