Q. A circular disc of radius 0.2 metre is placed in a uniform magnetic field of induction (1/π) Wb/m² in such a way that its axis makes an angle of 60° with B⃗. The magnetic flux linked with the disc is
A) 0.01 Wb
B) 0.02 Wb
C) 0.06 Wb
D) 0.08 Wb
Explanation
[Solution from source] The disc's area vector lies along its axis, so φ = BA cos 60° = (1/π)(π × 0.2²)(1/2) = 0.02 Wb. Using sin 60° (treating the angle as being with the plane of the disc) would give about 0.035 Wb. Answer (2).
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.