309 + Mcqs in Electrical Machine Design McqOptions

1.	*$_It is required to measure the true open circuit e.m.f. of a battery. The best device is?
A.	D.C. voltmeter
B.	Ammeter and a known resistance
C.	D.'potentiometer
D.	None of the above
Answer» D. None of the above

Discussion

2.	*$_The density of hydrogen is _____ times the density of air.?
A.	0.07
B.	1.5
C.	2.5
D.	3.5
Answer» B. 1.5

Discussion

3.	*$_If the current in a capacitor leads the voltage by 80¬¨‚àû, the loss angle of the capacitor is?
A.	10¬¨‚àû
B.	80¬¨‚àû
C.	120¬¨‚àû
D.	170¬¨‚àû
Answer» B. 80¬¨‚àû

Discussion

4.	*$_By which of the following methods the temperature rise of windings and other parts may be determined ??
A.	Thermometer method
B.	Resistance method
C.	Embedded temperature detector method
D.	Any of the above
Answer» E.

Discussion

5.	*$_A phase shifting transformer is used in conjunction with?
A.	D.C. potentiometer
B.	Drysdale potentiometer
C.	co-ordinate potentiometer
D.	Crompton potentiometer
Answer» C. co-ordinate potentiometer

Discussion

6.	/_In an AC co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be?
A.	out of phase by 90¬¨‚àû
B.	out of phase by 60¬¨‚àû
C.	out of phase by 30¬¨‚àû
D.	out of phase by 0¬¨‚àû
Answer» B. out of phase by 60¬¨‚àû

Discussion

7.	/_Which of the following methods does not take into account the maximum temperature rise under variable loadconditions ??
A.	Equivalent power method
B.	Equivalent current method
C.	Method of average losses
D.	Equivalent torque method
Answer» D. Equivalent torque method

Discussion

8.	/_E.m.f. of a Weston cell is accurately measured by?
A.	electrostatic voltmeter
B.	hot wire voltmeter
C.	isothermal voltmeter
D.	electrodynamic voltmeter
Answer» B. hot wire voltmeter

Discussion

9.	/_is usually used for brush rockers?
A.	Mild steel
B.	Copper
C.	Aluminium
D.	Cast-iron
Answer» E.

Discussion

10.	/_In a meggar controlling torque is provided by?
A.	spring
B.	gravity
C.	coil
D.	eddy current
Answer» D. eddy current

Discussion

11.	/_In D.C. machines the number of slots per pole usually lies?
A.	between 2 to 4
B.	between 6 to 8
C.	between 9 to 16
D.	between 20 to 30
Answer» D. between 20 to 30

Discussion

12.	/_In a low power factor wattmeter the compensating coil is connected?
A.	in series with current coil
B.	in parallel with current coil
C.	in series with pressure coil
D.	in parallel with pressure coil
Answer» D. in parallel with pressure coil

Discussion

13.	/________ instruments are those which measure the total quantity of electricity delivered in a particular time.?
A.	Absolute
B.	Indicating
C.	Recording
D.	Integrating
Answer» E.

Discussion

14.	/_A dynamometer wattmeter can be used for?
A.	both D.C. and A.C.
B.	D.C. only
C.	A.C. only
D.	any of the above
Answer» B. D.C. only

Discussion

15.	/_The flash point of transformer oil should be higher than?
A.	40¬¨‚àûC
B.	60¬¨‚àûC
C.	80¬¨‚àûC
D.	104¬¨‚àûC
Answer» E.

Discussion

16.	/_The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc.?
A.	conduction
B.	convection
C.	radiation
D.	any of the above
Answer» D. any of the above

Discussion

17.	/_The desirable static characteristics of a measuring system are?
A.	accuracy and reproducibility
B.	accuracy, sensitivity and reproducibility
C.	drift and dead zone
D.	static error
Answer» C. drift and dead zone

Discussion

18.	/_Which of the following meters are not used on D.C. circuits?
A.	Mercury motor meters
B.	Commutator motor meters
C.	Induction meters
D.	None of the above
Answer» D. None of the above

Discussion

19.	/_The mcrease in heat dissipation by air blasts is due to increase in?
A.	conduction
B.	convection
C.	radiation
D.	any ofthe above
Answer» C. radiation

Discussion

20.	/_The operation of a D.C. machine with large air gap lengths is comparatively?
A.	quiet
B.	noisy
C.	either of the above
D.	none of the above
Answer» B. noisy

Discussion

21.	/_Commonly used standard capacitor is?
A.	spherical type
B.	concentric cylindrical type
C.	electrostatic type
D.	multilayer parallel plate type
Answer» C. electrostatic type

Discussion

22.	/_The power of a n-phase circuit can be measured by using a minimum of?
A.	(n ‚Äö√Ñ√¨ 1) wattmeter elements
B.	n wattmeter elements
C.	(n + 1) wattmeter elements
D.	2n wattmeter elements
Answer» B. n wattmeter elements

Discussion

23.	/_A power factor meter has?
A.	one current circuit and two pressure circuits
B.	one current circuit and one pressure circuit
C.	two current circuits and one pres¬¨¬®sure circuit
D.	none of the above
Answer» B. one current circuit and one pressure circuit

Discussion

24.	/_The power factor of a single phase load can be calculated if the instruments available are?
A.	one voltmeter and one ammeter
B.	one voltmeter, one ammeter and one wattmeter
C.	one voltmeter, one ammeter and one energy meter
D.	any of the above
Answer» C. one voltmeter, one ammeter and one energy meter

Discussion

25.	/_In order to achieve high accuracy, the slide wire of a potentiometer should be?
A.	as long as possible
B.	as short as possible
C.	neither too small not too large
D.	very thick
Answer» B. as short as possible

Discussion

26.	/_Standard resistor is made from?
A.	platinum
B.	maganin
C.	silver
D.	nichrome
Answer» C. silver

Discussion

27.	/_The household energy meter is?
A.	an indicating instrument
B.	a recording instrument
C.	an integrating instrument
D.	none of the above
Answer» D. none of the above

Discussion

28.	/_Electrical machines having a power output up to about 750 W may be called_______machines.?
A.	small size
B.	medium size
C.	large size
D.	any of the above
Answer» B. medium size

Discussion

29.	/_In an Anderson bridge, the unknown inductance is measured in terms of?
A.	known inductance and resistance
B.	known capacitance and resistance
C.	known resistance
D.	known inductance
Answer» C. known resistance

Discussion

30.	/_A Weston synchronoscope is a?
A.	moving coil instrument
B.	moving iron instrument
C.	dynamometer instrument
D.	none of the above
Answer» D. none of the above

Discussion

31.	/_The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density.?
A.	air
B.	hydrogen
C.	either (A) or (B)
D.	none of the above
Answer» C. either (A) or (B)

Discussion

32.	/_The winding where dummy coils are used is sometimes called?
A.	Duplex winding
B.	Triplex winding
C.	Forced winding
D.	None of the above
Answer» D. None of the above

Discussion

33.	/_An ammeter is a?
A.	secondary instrument
B.	absolute instrument
C.	recording instrument
D.	integrating instrument
Answer» B. absolute instrument

Discussion

34.	/_A voltage of about 200 V can be measured?
A.	directly by a D.C. potentiometer
B.	a D.C. potentiometer in conjunction with a volt ratio box
C.	a D.C. potentiometer in conjunction with a known resistance
D.	none of the above
Answer» C. a D.C. potentiometer in conjunction with a known resistance

Discussion

35.	/_To avoid the effect of stray magnetic field in A.C. bridges we can use?
A.	magnetic screening
B.	Wagner earthing device
C.	wave filters
D.	any of the above
Answer» B. Wagner earthing device

Discussion

36.	/_The function of shunt in an ammeter is to?
A.	by pass the current
B.	increase the sensitivity of the ammeter
C.	increase the resistance of ammeter
D.	none of the above
Answer» B. increase the sensitivity of the ammeter

Discussion

37.	/_In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft.?
A.	small
B.	medium
C.	large
D.	any of the above
Answer» D. any of the above

Discussion

38.	/_In induction motors, the length of air gap in kept as small as mechanically possible is order to have?
A.	low power factor
B.	high power factor
C.	high over load capacity
D.	any of the above
Answer» C. high over load capacity

Discussion

39.	/_In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was?
A.	unity
B.	0.8 lagging
C.	0.8 leading
D.	zero
Answer» B. 0.8 lagging

Discussion

40.	%_An ammeter is a_%
A.	secondary instrument
B.	absolute instrument
C.	recording instrument
D.	integrating instrument
Answer» B. absolute instrument

Discussion

41.	%_A voltage of about 200 V can be measured_%
A.	directly by a D.C. potentiometer
B.	a D.C. potentiometer in conjunction with a volt ratio box
C.	a D.C. potentiometer in conjunction with a known resistance
D.	none of the above
Answer» C. a D.C. potentiometer in conjunction with a known resistance

Discussion

42.	%_To avoid the effect of stray magnetic field in A.C. bridges we can use_%
A.	magnetic screening
B.	Wagner earthing device
C.	wave filters
D.	any of the above
Answer» B. Wagner earthing device

Discussion

43.	%_A Weston synchronoscope is a_%
A.	moving coil instrument
B.	moving iron instrument
C.	dynamometer instrument
D.	none of the above
Answer» D. none of the above

Discussion

44.	%_The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density._%
A.	air
B.	hydrogen
C.	either (A) or (B)
D.	none of the above
Answer» C. either (A) or (B)

Discussion

45.	%_The winding where dummy coils are used is sometimes called_%
A.	Duplex winding
B.	Triplex winding
C.	Forced winding
D.	None of the above
Answer» D. None of the above

Discussion

46.	%_The function of shunt in an ammeter is to_%
A.	by pass the current
B.	increase the sensitivity of the ammeter
C.	increase the resistance of ammeter
D.	none of the above
Answer» B. increase the sensitivity of the ammeter

Discussion

47.	_ For measuring current at high frequency we should use$?
A.	moving iron instrument
B.	electrostatic instrument
C.	thermocouple instrument
D.	none of the above
Answer» D. none of the above

Discussion

48.	_ In induction motors, the length of air gap in kept as small as mechanically possible is order to have$?
A.	low power factor
B.	high power factor
C.	high over load capacity
D.	any of the above
Answer» C. high over load capacity

Discussion

49.	_ In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was$?
A.	unity
B.	0.8 lagging
C.	0.8 leading
D.	zero
Answer» B. 0.8 lagging

Discussion

50.	_ In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft.$?
A.	small
B.	medium
C.	large
D.	any of the above
Answer» D. any of the above

Discussion

Explore topic-wise MCQs in Testing Subject.

*$_It is required to measure the true open circuit e.m.f. of a battery. The best device is?

*$_The density of hydrogen is _____ times the density of air.?

*$_If the current in a capacitor leads the voltage by 80¬¨‚àû, the loss angle of the capacitor is?

*$_By which of the following methods the temperature rise of windings and other parts may be determined ??

*$_A phase shifting transformer is used in conjunction with?

*/*_In an AC co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be?

*/*_Which of the following methods does not take into account the maximum temperature rise under variable loadconditions ??

*/*_E.m.f. of a Weston cell is accurately measured by?

*/*_is usually used for brush rockers?

*/*_In a meggar controlling torque is provided by?

*/*_In D.C. machines the number of slots per pole usually lies?

*/*_In a low power factor wattmeter the compensating coil is connected?

*/*________ instruments are those which measure the total quantity of electricity delivered in a particular time.?

*/*_A dynamometer wattmeter can be used for?

*/*_The flash point of transformer oil should be higher than?

*/*_The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc.?

*/*_The desirable static characteristics of a measuring system are?

*/*_Which of the following meters are not used on D.C. circuits?

*/*_The mcrease in heat dissipation by air blasts is due to increase in?

*/*_The operation of a D.C. machine with large air gap lengths is comparatively?

*/*_Commonly used standard capacitor is?

*/*_The power of a n-phase circuit can be measured by using a minimum of?

*/*_A power factor meter has?

*/*_The power factor of a single phase load can be calculated if the instruments available are?

*/*_In order to achieve high accuracy, the slide wire of a potentiometer should be?

*/*_Standard resistor is made from?

*/*_The household energy meter is?

*/*_Electrical machines having a power output up to about 750 W may be called_______machines.?

*/*_In an Anderson bridge, the unknown inductance is measured in terms of?

*/*_A Weston synchronoscope is a?

*/*_The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density.?

*/*_The winding where dummy coils are used is sometimes called?

*/*_An ammeter is a?

*/*_A voltage of about 200 V can be measured?

*/*_To avoid the effect of stray magnetic field in A.C. bridges we can use?

*/*_The function of shunt in an ammeter is to?

*/*_In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft.?

*/*_In induction motors, the length of air gap in kept as small as mechanically possible is order to have?

*/*_In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was?

%_An ammeter is a_%

%_A voltage of about 200 V can be measured_%

%_To avoid the effect of stray magnetic field in A.C. bridges we can use_%

%_A Weston synchronoscope is a_%

%_The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density._%

%_The winding where dummy coils are used is sometimes called_%

%_The function of shunt in an ammeter is to_%

_ For measuring current at high frequency we should use$?

_ In induction motors, the length of air gap in kept as small as mechanically possible is order to have$?

_ In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was$?

_ In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft.$?

/_In an AC co-ordinate potentiometer, the currents in the phase and quadrature potentiometer are adjusted to be?

/_Which of the following methods does not take into account the maximum temperature rise under variable loadconditions ??

/_E.m.f. of a Weston cell is accurately measured by?

/_is usually used for brush rockers?

/_In a meggar controlling torque is provided by?

/_In D.C. machines the number of slots per pole usually lies?

/_In a low power factor wattmeter the compensating coil is connected?

/________ instruments are those which measure the total quantity of electricity delivered in a particular time.?

/_A dynamometer wattmeter can be used for?

/_The flash point of transformer oil should be higher than?

/_The heat dissipated by from a surface depends upon its temperature and its characteristics like colour, roughness etc.?

/_The desirable static characteristics of a measuring system are?

/_Which of the following meters are not used on D.C. circuits?

/_The mcrease in heat dissipation by air blasts is due to increase in?

/_The operation of a D.C. machine with large air gap lengths is comparatively?

/_Commonly used standard capacitor is?

/_The power of a n-phase circuit can be measured by using a minimum of?

/_A power factor meter has?

/_The power factor of a single phase load can be calculated if the instruments available are?

/_In order to achieve high accuracy, the slide wire of a potentiometer should be?

/_Standard resistor is made from?

/_The household energy meter is?

/_Electrical machines having a power output up to about 750 W may be called_______machines.?

/_In an Anderson bridge, the unknown inductance is measured in terms of?

/_A Weston synchronoscope is a?

/_The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density.?

/_The winding where dummy coils are used is sometimes called?

/_An ammeter is a?

/_A voltage of about 200 V can be measured?

/_To avoid the effect of stray magnetic field in A.C. bridges we can use?

/_The function of shunt in an ammeter is to?

/_In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft.?

/_In induction motors, the length of air gap in kept as small as mechanically possible is order to have?

/_In a 3-phase power measurement by two wattmeter method, both the watt meters had identical readings. The power factor of the load was?