Question Detail

PHY 102 Electromagnetic Induction Objective Question

Question

In a DC motor, the relationship between applied voltage (V), back emf (ε_b), current (I), and resistance (R) is:
Options
A V + ε_b = IR
B V - ε_b = IR
Correct Answer
C V = ε_b + I/R
D V = ε_b R
Correct Answer

Option B is the correct answer.

Detailed Explanation

The net voltage across the motor is the applied voltage minus the back emf, and that equals I × R (Ohm's law for the armature resistance). So V - ε_b = IR.

Hint

Applied minus back emf equals IR.

Question Info