Question

Imagine that a steady current I flows in a straight cylindrical wire of radius R0 and resistivity ρ.

a) If the current is then changed at a rate dI/dt, find a displacement current ID in the wire.

Express your answer in terms of some or all of the variables R0, ρ, dI/dt, and appropriate constants.

Part B

If the current in a copper wire is changed at the rate of 0.50 A/ms , determine the magnitude of ID.

Part C

Determine the magnitude of the magnetic field BD (T) created by ID at the surface of a copper wire with R0 = 1.5 mm .

Express your answer to two significant figures and include the appropriate units.

Part D

Compare (as a ratio) BD with the field created at the surface of the wire by a steady current of 0.50 A .

Answer 1