A motor has an armature resistance $4 \Omega$. It is operating on 220 V. At its full speed, it develops a back emf of 200 V. The current in the armature when the motor is switched on will be:
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 55 A
The calculate the current in the momentum when the motor is switched on,
$I=\frac{V-E_b}{R_α}$
where,
$V$ (Applied voltage) = 220 V
$E_b$ (Back emf) = 200 V
$R_α$ (Armature Resistance) = 4 Ω
$∴I=\frac{220-200}{4}=5A$