Electromagnetic Induction · Class 12 · CBSE · Science Physics
A metal rod of length l is rotated with an angular velocity omega in a uniform magnetic field B, about an axis passing through one end and perpendicu…
Practice question from Electromagnetic Induction (Class 12 · CBSE · Science Physics), with the correct answer and a step-by-step solution.
medium · MCQ · Q-2B4DC8
A metal rod of length is rotated with an angular velocity in a uniform magnetic field , about an axis passing through one end and perpendicular to the rod, with the field also parallel to the axis of rotation. The induced emf across the ends of the rod is:
- A.\frac{1}{2} B \omega l^2
- B.B \omega l^2
- C.2 B \omega l^2
- D.0Correct answer
Solution
Motional emf is given by or rate of area sweeping perpendicular to the magnetic field. Here, the magnetic field is parallel to the axis of rotation and thus parallel to the plane of motion of the rod, meaning no magnetic field lines are cut by the rod. Therefore, the induced emf is zero.
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