In a circle of radius R the perpendicular field changes with time according to B = a + bt. OPQ is the triangular wire loop shown, with O the circle centre and angle POQ = 60°. Its resistance per unit length is λ. The induced current is πbR(√3−1)/[3n√3 λ]. Find n.
Physics · Mixed Chapter
JEE Mains

Question

In a circle of radius R the perpendicular field changes with time according to B = a + bt. OPQ is the triangular wire loop shown, with O the circle centre and angle POQ = 60°. Its resistance per unit length is λ. The induced current is πbR(√3−1)/[3n√3 λ]. Find n.

Physics · Mixed Chapter

G1 Physics · Accepted Answer

Explanation: Faraday emf magnitude is |dB/dt|×(area of the loop inside the time-varying-field region). Divide the field-overlap flux by wire resistance λ(OP+PQ+QO) using the 60° geometry. The geometry in the original figure leads to the displayed coefficient with n=4; verify the tangency construction against the source drawing.