MCQ
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 downwards parallel to itself
  • 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

Answer

Correct option: C.
The rod $CD$ will move upward and turn clockwise at the same time
c
since the force on the rod $\mathrm{CD}$ 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.

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