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Electromagnetic Induction — JEE physics STD 12 Science — Question

CBSE BoardEnglish MediumSTD 12 ScienceJEE physicsElectromagnetic Induction1 Mark
MCQ
When the speed of a dc motor increases the armature current
  • A
    Increases
  • ✓
    Decreases
  • C
    Does not change
  • D
    Increases and decreases continuously
✓

Answer

Correct option: B.
Decreases
With the increasing speed, $\omega$ increases. Thus current reduces due to increase in the back e.m.f.Moreover $i=\frac{V-K \omega}{R}$. More $\omega$ will lead to the lesser current.

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