For the same circular capacitor of plate radius R being charged by current I, the magnetic field at a distance r > R from the axis is:
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Question

For the same circular capacitor of plate radius R being charged by current I, the magnetic field at a distance r > R from the axis is:

G1 Physics · Accepted Answer

For r > R, the Amperian loop encloses the complete electric-flux region between the capacitor plates. Therefore the enclosed displacement current is equal to the full charging current I. Ampere-Maxwell law gives B(2πr) = μ₀I. Hence, B = μ₀I/(2πr). Correct option: A.