A long cylindrical conductor of radius a along the z-axis has internal magnetic field B(r)=μ₀J₀r(3-2r/a)/6. Which statements are correct?
Select all that apply

Question

A long cylindrical conductor of radius a along the z-axis has internal magnetic field B(r)=μ₀J₀r(3−2r/a)/6. Which statements are correct?

G1 Physics · Accepted Answer

Ampere's law gives J(r)=(1/μ₀r)d[rB(r)]/dr. For B=μ₀J₀r(3−2r/a)/6, J(r)=J₀(1−r/a), maximum at r=0. Integrating J over the cross-section gives I=πJ₀a²/3. Thus A and C are correct.