Physics · Electromagnetic induction: Faraday's law, induced emf and current, Lenz's law, eddy currents, self and mutual inductance
A thick strip of copper is mounted as a compound pendulum about O.If it is made
A thick strip of copper is mounted as a compound pendulum about O.If it is made to swing through a uniform magnetic field B normal to the plane of the strip then (neglecting air resistance) it is found that
- A. strip swings almost freely.
- B. motion of the strip is heavily damped.
- C. strip does not oscillate at all but immediately comes to rest in the vertical position
- D. strip swings almost freely but its temperature decreases
Step-by-step solution
As the copper strip swings in the magnetic field, it cuts magnetic flux lines, inducing eddy currents in the conductor. According to Lenz's law, these currents produce a magnetic force that opposes the motion, causing damping. Since copper is a good conductor, the eddy currents are strong, leading to heavy damping of the pendulum's oscillations.
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