28 + Mcqs in Dc Machine Applications Page 1 McqOptions

1.	A d.c. generator has been provided tappings on the armature winding at intervals of 120 degrees from the side of commutator. The connection will be __________
A.	delta connected alternator
B.	star connected alternator
C.	star connected induction motor
D.	any of the mentioned
Answer» B. star connected alternator

Discussion

2.	A 200 V dc motor has external resistances of Ra and Rf in armature and field circuits respectively. The starting current is reduced when?
A.	Ra is maximum and Rf minimum
B.	Rf is maximum and Ra minimum
C.	Ra is minimum and Rf minimum
D.	Ra is maximum and Rf maximum
Answer» B. Rf is maximum and Ra minimum

Discussion

3.	If a dc shunt motor is stopped by forcing starter handle back to OFF position, then the __________
A.	dangerous sparking occurs at last stud
B.	dangerous sparking occurs at all stud
C.	it stops normally
D.	heavy sparking
Answer» B. dangerous sparking occurs at all stud

Discussion

4.	Long back ago, magnetic casette were in use, having permanent magnet dc motors which had?
A.	magnets on stator and armature on rotor
B.	magnet on rotor and armature on stator
C.	electronic commutation
D.	all of the mentioned
Answer» B. magnet on rotor and armature on stator

Discussion

5.	Most commercial compound dc generator are normally supplied by manufacturers as ______ compounded machines.
A.	over
B.	under
C.	level
D.	none of the mentioned
Answer» B. under

Discussion

6.	Which of the following are applied with differential compound motor?
A.	Hoist
B.	Cranes
C.	Drilling machines
D.	None of the mentioned
Answer» B. Cranes

Discussion

7.	Most commercial compound dc generator are normally supplied by manufacturers as over compound machines because __________
A.	degree of compounding can be adjusted by diverters acrosss series field
B.	they have ideally best for HVDC
C.	cost effective than shunt
D.	zero percent regulation
Answer» B. they have ideally best for HVDC

Discussion

8.	Centrifugal pumps, fans-blowers use __________
A.	shunt as well as induction motor
B.	only shunt motors
C.	only induction motor
D.	none of the mentioned
Answer» B. only shunt motors

Discussion

9.	The manufacturer has mentioned a medium starting torque and 15% speed regulation. Which is the most appropriate motor for this requirement?
A.	dc shunt motor
B.	induction motor
C.	differential motor
D.	none of the mentioned
Answer» B. induction motor

Discussion

10.	There is an application which required pulsating loads, punch presses. The most preferred machines would be __________
A.	compound dc machine
B.	series dc machine
C.	shunt dc machine
D.	all of the mentioned
Answer» B. series dc machine

Discussion

11.	Maximum torque in dc series motor is limited by __________
A.	commutation
B.	heating
C.	field control
D.	all of the mentioned
Answer» B. heating

Discussion

12.	Separately excited dc generators are used in __________
A.	Ward leonard system of speed control
B.	Hopkinson’s testing
C.	Voltage control
D.	None of the mentioned
Answer» B. Hopkinson’s testing

Discussion

13.	Inspite of heavy initial investments, dc motors are used due to _____________
A.	flexibility and ease of control
B.	lower losses
C.	improved power factor of the system
D.	all of the mentioned
Answer» B. lower losses

Discussion

14.	WHICH_OF_THE_FOLLOWING_ARE_APPLIED_WITH_DIFFERENTIAL_COMPOUND_MOTOR??$
A.	Hoist
B.	Cranes
C.	Drilling machines
D.	None of the mentioned
Answer» B. Cranes

Discussion

15.	Long back ago, magnetic casette were in use, having permanent magnet dc motors which had$
A.	magnets on stator and armature on rotor
B.	magnet on rotor and armature on stator
C.	electronic commutation
D.	all of the mentioned
Answer» B. magnet on rotor and armature on stator

Discussion

16.	Most_commercial_compound_dc_generator_are_normally_supplied_by_manufacturers_as________compounded_machines.$
A.	over
B.	under
C.	level
D.	none of the mentioned
Answer» B. under

Discussion

17.	A d.c. generator has been provided tappings on the armature winding at intervals of 120 degrees from the side of commutator. The connection will be
A.	delta connected alternator
B.	star connected alternator
C.	star connected induction motor
D.	any of the mentioned
Answer» B. star connected alternator

Discussion

18.	A 200 V dc motor has external resistances of Ra and Rf in armature and field circuits respectively. The starting current is reduced when
A.	Ra is maximum and Rf minimum
B.	Rf is maximum and Ra minimum
C.	Ra is minimum and Rf minimum
D.	Ra is maximum and Rf maximum
Answer» B. Rf is maximum and Ra minimum

Discussion

19.	Interpoles are used to start the dc motor above the base speed.
A.	True
B.	False
Answer» C.

Discussion

20.	If a dc shunt motor is stopped by forcing starter handle back to OFF position, then
A.	dangerous sparking occurs at last stud
B.	dangerous sparking occurs at all stud
C.	it stops normally
D.	heavy sparking
Answer» B. dangerous sparking occurs at all stud

Discussion

21.	Most commercial compound dc generator are normally supplied by manufacturers as over compound machines becaus?
A.	degree of compounding can be adjusted by diverters acrosss series field
B.	they have ideally best for HVDC
C.	cost effective than shunt
D.	zero percent regulation
Answer» B. they have ideally best for HVDC

Discussion

22.	Centrifugal pumps, fans-blowers use
A.	shunt as well as induction motor
B.	only shunt motors
C.	only induction motor
D.	none of the mentioned
Answer» B. only shunt motors

Discussion

23.	The manufacturer has mentioned a medium starting torque and 15% speed regulation. The most appropriate motor for his requirement is
A.	dc shunt motor
B.	induction motor
C.	differential motor
D.	none of the mentioned
Answer» B. induction motor

Discussion

24.	There is an application which required pulsating loads, punch presses. The most preferred machines would be
A.	compound dc machine
B.	series dc machine
C.	shunt dc machine
D.	all of the mentioned
Answer» B. series dc machine

Discussion

25.	Hoists, cranes and battery powered vehicles use _________ motors in the locomotive.
A.	dc series
B.	dc shunt
C.	induction
D.	reluctance
Answer» B. dc shunt

Discussion

26.	Maximum torque in dc series motor is limited by
A.	commutation
B.	heating
C.	field control
D.	all of the mentioned
Answer» B. heating

Discussion

27.	Separately excited dc generators are used in
A.	Ward leonard system of speed control
B.	Hopkinson‚Äö√Ñ√∂‚àö√ë‚àö¬•s testing
C.	Voltage control
D.	None of the mentioned
Answer» B. Hopkinson‚Äö√Ñ√∂‚àö√ë‚àö¬•s testing

Discussion

28.	Inspite of heavy initial investments, dc motors are used due to
A.	flexibility and ease of control
B.	lower losses
C.	improved power factor of the system
D.	all of the mentioned
Answer» B. lower losses

Discussion

Explore topic-wise MCQs in Electrical Machines.

A d.c. generator has been provided tappings on the armature winding at intervals of 120 degrees from the side of commutator. The connection will be __________

A 200 V dc motor has external resistances of Ra and Rf in armature and field circuits respectively. The starting current is reduced when?

If a dc shunt motor is stopped by forcing starter handle back to OFF position, then the __________

Long back ago, magnetic casette were in use, having permanent magnet dc motors which had?

Most commercial compound dc generator are normally supplied by manufacturers as ______ compounded machines.

Which of the following are applied with differential compound motor?

Most commercial compound dc generator are normally supplied by manufacturers as over compound machines because __________

Centrifugal pumps, fans-blowers use __________

The manufacturer has mentioned a medium starting torque and 15% speed regulation. Which is the most appropriate motor for this requirement?

There is an application which required pulsating loads, punch presses. The most preferred machines would be __________

Maximum torque in dc series motor is limited by __________

Separately excited dc generators are used in __________

Inspite of heavy initial investments, dc motors are used due to _____________

WHICH_OF_THE_FOLLOWING_ARE_APPLIED_WITH_DIFFERENTIAL_COMPOUND_MOTOR??$

Long back ago, magnetic casette were in use, having permanent magnet dc motors which had$

Most_commercial_compound_dc_generator_are_normally_supplied_by_manufacturers_as________compounded_machines.$

A d.c. generator has been provided tappings on the armature winding at intervals of 120 degrees from the side of commutator. The connection will be

A 200 V dc motor has external resistances of Ra and Rf in armature and field circuits respectively. The starting current is reduced when

Interpoles are used to start the dc motor above the base speed.

If a dc shunt motor is stopped by forcing starter handle back to OFF position, then

Most commercial compound dc generator are normally supplied by manufacturers as over compound machines becaus?

Centrifugal pumps, fans-blowers use

The manufacturer has mentioned a medium starting torque and 15% speed regulation. The most appropriate motor for his requirement is

There is an application which required pulsating loads, punch presses. The most preferred machines would be

Hoists, cranes and battery powered vehicles use _________ motors in the locomotive.

Maximum torque in dc series motor is limited by

Separately excited dc generators are used in

Inspite of heavy initial investments, dc motors are used due to