Q. An infinitely long straight conductor $AB$ is fixed and a current is passed through it. Another movable straight wire $CD$ of finite length and carrying current is held perpendicular to it and released. Neglect weight of the wire
A) The rod $CD$ will move upwards parallel to itself
B) The rod $CD$ will move downward parallel to itself
C) The rod $CD$ will move upward and turn clockwise at the same time
D) The rod $CD$ will move upward and turn anti-clockwise at the same time
Explanation
(c) Since the force on the rod $CD$ is non-uniform it will experience force and torque. From the left hand side it can be seen that the force will be upward and torque is clockwise
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.