If the current in the coil itself is increased by rheostat, the emf induced will be:
Correct answer: A. Opposite to that of battery
- A. Opposite to that of battery
- B. In the same direction at that of battery
- C. Both (a) and(b)
- D. None of these
Explanation
When the current in the coil itself is increased by a rheostat, it means the rate of change of current is also increasing. According to Faraday's law of electromagnetic induction, an electromotive force (EMF) is induced in a coil when there is a change in the magnetic flux through the coil. The induced EMF opposes the change that produces it. So, if the current in the coil itself is increased, the induced EMF will be in the opposite direction to that of the battery, so this option is correct: Opposite to that of the battery
Last updated
About Electromagnetic Induction
Changing magnetic flux induces an emf according to Faraday's law, while Lenz's law gives the direction that opposes the change producing it. Transformers apply induction between coils to step alternating voltage up or down, with turns ratio, current transformation and energy losses determining practical operation.
Practise Electromagnetic Induction
288 free Electromagnetic Induction MCQs from Physics, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Physics questions like this
Physics is on 13 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A 25 wattand 100 watt bulbs are joined in series and connected to the mains.Which bulb will glow brighter?
A 50 mH coil carries a current of 2A. The energy stored in its magnetic field is:
A.C generator is a device which converts:
A.C is converted into D.C by:
A coil has an inductance of 0.02 Henry. When a current in the coil is changing at the rate of 150 A/S then the induced emf will be: