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PhysicsNEET 2019Biot–Savart and Ampère's laws

Moving Charges and Magnetism

A cylindrical conductor of radius RR carries a constant current, uniformly distributed over its cross-section. Which of the following best describes the magnitude of the magnetic field BB as a function of the distance dd from the axis of the conductor?

  1. A.BB rises to a peak before d=Rd=R, then drops sharply to zero at d=Rd=R and stays zero for d>Rd>R
  2. B.BB is zero for d<Rd<R, then jumps up sharply at d=Rd=R and stays at that high value for d>Rd>R
  3. C.BB increases linearly with dd for d<Rd<R, reaches its maximum at d=Rd=R, and decreases (as 1/d1/d) for d>Rd>R✓
  4. D.BB is zero for d<Rd<R, then rises and levels off to a constant value for d>Rd>R

You have the answer. The worked solution — and why the other three were written — is part of a paid pack.

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