Question

Question 1

A 220 V, 1000 rpm, DC Shunt Motor has armature resistance of0.10 W, resistance of shunt windings is 220 W . Determine external resistance required to limit the starting current to 120 A.

Your Answer:

Question 2 (1 point)

A 220 V, 1000 rpm, DC Shunt Motor has armature resistance of 0.10 W, resistance of shunt windings is 220 W . Determine current of the motor at standstill (starting) in Amps.

Your Answer:
Question 3

The mechanical power developed by the armature of a dc motor is equal to

	power output plus iron losses
	power input minus losses
	armature current multiplied by the back emf
	power output multiplied by the efficiency

Question 4 (1 point)

The DC series motor should never be switched on at no load because

	the machine does not pick up
	the speed becomes dangerously high
	it will take too long to accelerate
	the field current is zero

Question 5 (1 point)

A DC shunt motor has an armature resistance of 0.24 W, and draws an armature current of 80 A at 300 V. The machine has 8 poles and 800 lap wound conductors. The flux per pole is 0.042 Wb.

Calculate the Torque developed by the armature

Your Answer:

Question 6

A 4 pole lap wound 220 V DC series motor has 200 slots with 6 conductors per slot. The current drawn by the motor is 40 A and flux per pole is 16 mWb. The armature resistance is 0.46 ohm and field resistance is 0.26 W.

Calculate speed of the rotor

Your Answer:

Answer 1