In an alternating current generator, the emf induced in the rotating coil is maximum when the plane of the coil is
Correct answer: B. parallel to the magnetic field
- A. perpendicular to the magnetic field
- B. parallel to the magnetic field
- C. at 45 degrees to the field
- D. irrelevant, since the emf is constant
Explanation
The emf depends on the rate of change of flux, not on the flux itself, and that rate is greatest when the coil is edge on to the field, precisely where the flux through it is momentarily zero. When the plane is perpendicular to the field the flux is maximum but is instantaneously stationary, so the emf is zero. This quarter cycle offset between flux and emf is what makes the output sinusoidal.
Report an error
The more specific you are, the faster it gets fixed. A source beats an opinion.
Prefer email? support@testustad.com
About Faraday's Law
Faraday's law states that an induced electromotive force equals the rate of change of magnetic flux linkage through a circuit. Questions cover changing field, area, angle or motion, the negative sign associated with Lenz's law, and the distinction between induced emf and the current that may flow in a closed circuit.
Practise Electromagnetic Induction
288 free Electromagnetic Induction MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Discussion
Stuck on an option, or know a faster way to get there? Ask or explain it here.
No comments yet. Be the first to explain this one.
Exams that ask Physics questions like this
Physics is on 16 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
More Faraday's Law questions
The SI unit of inductance is the
Self induction is the property by which a coil
A bar magnet is held stationary inside a coil. The induced emf in the coil is
Which change would NOT increase the emf induced in a coil by a moving magnet?
A straight conductor of length 0.5 m moves at 4 m per second perpendicular to a field of 0.2 T. The emf induced across its ends is
An electric motor could be used as a: ___________?