Question

What does ( Ia ) indicate in the voltage equation of a DC motor? [ V = Eb + Ia Ra ]

• A. Input voltage
• B. Back emf
• C. Armature current
• D. Armature resistance

Answer 1

The Correct Option is C

In the voltage equation of a DC motor, [ V = Eb + Ia Ra, ] where
(V) is the applied voltage to the armature,
(Eb) is the back electromotive force (emf) generated due to the motor’s rotation,
(Ia) is the armature current, which is the current flowing through the motor’s armature winding,
(Ra) is the resistance of the armature winding.
The armature current (Ia) is crucial because it directly influences the torque produced by the motor. The voltage equation balances the applied voltage with the back emf and the voltage drop across the armature resistance due to (Ia).