Home/
Competitive Exams/
JEE Main & Advanced/
Physics/
Electromagnetic Induction and Alternating Current/
Question 20182
JEE Physics · Medium

Electromagnetic Induction and Alternating Current: Back EMF in DC Motor MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
Back EMF in DC MotorMediumQuestion 20182

Question

Back EMF in a DC motor is caused by:
  1. A
    Friction losses in bearings
  2. B
    Electromagnetic induction due to the rotating armature in the magnetic field
    Correct
  3. C
    Resistance of the armature winding
  4. D
    The supply voltage

Correct answer

Electromagnetic induction due to the rotating armature in the magnetic field

Explanation

As the armature rotates, it acts as a generator, inducing an EMF that opposes the supply voltage (Lenz's law). This back EMF limits current and represents mechanical power output conversion.

Review Electromagnetic Induction and Alternating Current notesStart timed chapter practice