A cylindrical conductor of radius R carries a uniform steady current. Which graph correctly shows magnetic field B as a function of distance d from its centre? [Image]
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A cylindrical conductor of radius R carries a uniform steady current. Which graph correctly shows magnetic field B as a function of distance d from its centre? [Image]

G1 Physics · Accepted Answer

Step 1: Inside a uniformly current-filled cylindrical conductor, B(r)=μ₀Ir/(2πR²) and grows linearly with radial distance. Step 2: At surface r=R the field is maximum B(R)=μ₀I/(2πR). Step 3: Outside conductor B(r)=μ₀I/(2πr), so it decreases hyperbolically. Graph B. Final answer: (B), refer to source diagram / graph.