In a DC generator the emf generated by the armature is maximum when
A. rate of change of flux is maximum.
B. rate of change of flux is minimum.
C. induced voltage is high.
D. shaft rotation is high.
Answer: A
Share your understanding of this question with the correct explanation.
The emf generated by the armature of a DC generator is maximum when the rate of change of flux is maximum. This is based on Faraday’s law of electromagnetic induction, which states that the magnitude of the induced electromotive force (emf) in a conductor is directly proportional to the rate of change of magnetic flux passing through the conductor.
In a DC generator, the armature rotates within a magnetic field produced by the field winding. As the armature rotates, the magnetic flux passing through the armature coil changes. The rate at which this flux changes is directly related to the speed of rotation and the number of magnetic field lines passing through the armature coil.
When the rate of change of flux is at its maximum, the induced emf in the armature coil is also at its maximum. This occurs when the armature coil is cutting through the magnetic field lines at the fastest rate, typically when the armature is in a position perpendicular to the magnetic field lines.
Therefore, the correct answer is option A: “Rate of change of flux is maximum.”