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Question
Write some of the important uses of electromagnets.
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Solution
- Electromagnets are used by doctors in MRI scanners.
- It is used for treating knee pain by using pulsing electromagnetic fields (PEMF).
- It is used in magnetic levitation trains.
RELATED QUESTIONS
A line charge λ per unit length is lodged uniformly onto the rim of a wheel of mass M and radius R. The wheel has light non-conducting spokes and is free to rotate without friction about its axis (Figure). A uniform magnetic field extends over a circular region within the rim. It is given by,
B = − B0 k (r ≤ a; a < R)
= 0 (otherwise)
What is the angular velocity of the wheel after the field is suddenly switched off?

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