Two equal circular loops of radius R form a figure-of-eight wire. Their planes are inclined at 120° and each carries current I. The resultant induction at the common intersection of the loop axes is (N μ₀I)/(48R). Determine N.
Physics · Mixed Chapter
JEE Main Practice

Question

Two equal circular loops of radius R form a figure-of-eight wire. Their planes are inclined at 120° and each carries current I. The resultant induction at the common intersection of the loop axes is (N μ₀I)/(48R). Determine N.

Physics · Mixed Chapter

G1 Physics · Accepted Answer

Step 1 — Each circular loop contributes an axial field of magnitude μ₀I/(2R) at its centre. Step 2 — Use the actual figure-of-eight current directions and the 120° angle between loop planes to vector-add the two contributions at P. Step 3 — Source specifies B = Nμ₀I/(48R) and prints N = 3. QUALITY FLAG — The position of P relative to loop centres is not fixed by the prose alone, and the source contains no clear dimensioned diagram. Printed answer 3 is included but not independently verified.