Q. In an A.C. generator, when the plane of the armature is perpendicular to the magnetic field
A) Both magnetic flux and emf are maximum
B) Both magnetic flux and emf are zero
C) Both magnetic flux and emf are half of their respective maximum values
D) Magnetic flux is maximum and emf is zero
Explanation
(d) Magnetic field, $\phi_{B} = BA\cos\theta$
Where $\theta$ is the angle between normal to the plane of the coil and magnetic field
Induced emf, $\varepsilon = BA\sin\theta$
Here, $\theta = 0{^\circ}$
$\therefore$ Magnetic flux is maximum and induced emf is zero
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.