NEETPhysicsMagnetic Effects of Current
Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): For a long straight solid wire carrying a uniform steady current, the magnitude of the magnetic field is maximum at the axis of the wire. Reason (R): The magnetic field inside the solid wire increases linearly with distance from the axis, and outside the wire it decreases inversely with distance. I
Options
- ABoth (A) and (R) are correct and (R) is the correct explanation of (A)
- BBoth (A) and (R) are correct but (R) is not the correct explanation of (A)
- C(A) is correct but (R) is not correct
- D(A) is not correct but (R) is correct
Correct answer
D. (A) is not correct but (R) is correct
Step-by-step solution
Assertion (A) is not correct. For a long straight solid wire carrying a uniform steady current, the magnetic field at the axis ( r = 0 ) is zero. The magnitude of the magnetic field is maximum at the surface of the wire ( r = R ). Reason (R) is correct. By Ampere's circuital law, the magnetic field inside a solid wire with uniform current density ( r Therefore, (A) is not correct but (R) is correct. Answer: (A) is not correct but (R) is correct