MCQOPTIONS
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MCQOPTIONS
This section includes 309 Mcqs, each offering curated multiple-choice questions to sharpen your Electrical Engineering knowledge and support exam preparation. Choose a topic below to get started.
| 51. |
In a Weston frequency meter, the magnetic axes of the two fixed coils are |
| A. | arallel |
| B. | erpendicular |
| Answer» C. | |
| 52. |
Which of the following methods is used for air cooling of turbo-alternators ? |
| A. | ne sided axial ventilation |
| B. | wo sided axial ventilation |
| C. | ultiple inlet system |
| D. | ll of the above |
| Answer» E. | |
| 53. |
The efficiency of a machine should be as ______ as possible to reduce the operating cost. |
| A. | igh |
| B. | ow |
| C. | ither of the above |
| D. | one of the above |
| Answer» B. ow | |
| 54. |
In D.C. machines the width of the duct is usually |
| A. | mm |
| B. | mm |
| C. | mm |
| D. | 0 mm |
| Answer» E. | |
| 55. |
The density of hydrogen is _____ times the density of air. |
| A. | 0.07 |
| B. | 0.5 |
| C. | 0.5 |
| D. | 0.5 |
| Answer» B. 0.5 | |
| 56. |
To measure a resistance with the help of a potentiometer it is |
| A. | ecessary to standardise the potentiometer |
| B. | ot necessary to standardise the potentiometer |
| C. | ecessary to use a volt ratio box in conjunction with the potentiometer |
| D. | one of the above |
| Answer» C. ecessary to use a volt ratio box in conjunction with the potentiometer | |
| 57. |
Wattmeter cannot be designed on the principle of |
| A. | lectrostatic instrument |
| B. | hermocouple instrument |
| C. | oving iron instrument |
| D. | lectrodynamic instrument |
| Answer» D. lectrodynamic instrument | |
| 58. |
If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is |
| A. | 0° |
| B. | 0° |
| C. | 20° |
| D. | 70° |
| Answer» B. 0° | |
| 59. |
The noise produced by a ______ cooled machine is less as the rotor moves in a medium of smaller density. |
| A. | ir |
| B. | ydrogen |
| C. | ither (A) or (B) |
| D. | one of the above |
| Answer» C. ither (A) or (B) | |
| 60. |
Which of the following is the commonly used type of electromagnets ? |
| A. | lat-faced armature type |
| B. | orse shoe type |
| C. | lat-faced plunger type |
| D. | ll of the above |
| Answer» E. | |
| 61. |
With conventional hydrogen cooling it is possible to increase the rating of a single unit to |
| A. | 0 MW |
| B. | 00 MW |
| C. | 00 MW |
| D. | one of the above |
| Answer» D. one of the above | |
| 62. |
The voltage control in electric supply networks in required on account of which of the following reasons ? |
| A. | djustment of voltage at consumers premises within statutory limits |
| B. | ontrol of active and reactive power |
| C. | djustment of short period daily and seasonal voltage variations in accordance with variations of load |
| D. | ll of the above |
| Answer» E. | |
| 63. |
The value of exciting or magnetizing current depends upon which of the following factors ? |
| A. | otal m.m.f. required |
| B. | he number of turns in the exciting winding |
| C. | he way in which the winding is distributed |
| D. | ll of the above |
| Answer» E. | |
| 64. |
By which of the following methods the temperature rise of windings and other parts may be determined ? |
| A. | hermometer method |
| B. | esistance method |
| C. | mbedded temperature detector method |
| D. | ny of the above |
| Answer» E. | |
| 65. |
The winding where dummy coils are used is sometimes called |
| A. | uplex winding |
| B. | riplex winding |
| C. | orced winding |
| D. | one of the above |
| Answer» D. one of the above | |
| 66. |
In Weston synchronoscope the moving coil is connected across |
| A. | us-bars |
| B. | ncoming alternator |
| C. | ixed coils |
| D. | ny of the above |
| Answer» B. ncoming alternator | |
| 67. |
is usually used for brush rockers |
| A. | ild steel |
| B. | opper |
| C. | luminium |
| D. | ast-iron |
| Answer» E. | |
| 68. |
In ______ machines, the size of the shaft is decided by the critical speed which depends on the deflection of the shaft. |
| A. | mall |
| B. | edium |
| C. | arge |
| D. | ny of the above |
| Answer» D. ny of the above | |
| 69. |
A moving-coil permanent-magnet instrument can be used as flux meter |
| A. | y using a low resistance shunt |
| B. | y using a high series resistance |
| C. | y eliminating the control springs |
| D. | y making control springs of large moment of inertia |
| Answer» D. y making control springs of large moment of inertia | |
| 70. |
E.m.f. of a Weston cell is accurately measured by |
| A. | lectrostatic voltmeter |
| B. | ot wire voltmeter |
| C. | sothermal voltmeter |
| D. | lectrodynamic voltmeter |
| Answer» B. ot wire voltmeter | |
| 71. |
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. | nity |
| B. | .8 lagging |
| C. | .8 leading |
| D. | ero |
| Answer» B. .8 lagging | |
| 72. |
The distance between the starts of two consecutive coils measured in terms of coil sides is called |
| A. | ront pitch |
| B. | inding pitch |
| C. | ommutator pitch |
| D. | ack pitch |
| Answer» C. ommutator pitch | |
| 73. |
The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following? |
| A. | orrugations |
| B. | ins |
| C. | ubes |
| D. | ll of the above |
| Answer» E. | |
| 74. |
Which of the following methods does not take into account the maximum temperature rise under variable loadconditions ? |
| A. | quivalent power method |
| B. | quivalent current method |
| C. | ethod of average losses |
| D. | quivalent torque method |
| Answer» D. quivalent torque method | |
| 75. |
In induction motors, the length of air gap in kept as small as mechanically possible is order to have |
| A. | ow power factor |
| B. | igh power factor |
| C. | igh over load capacity |
| D. | ny of the above |
| Answer» C. igh over load capacity | |
| 76. |
With direct water cooling it is possible to have ratings of about |
| A. | 00 MW |
| B. | 00 MW |
| C. | 00 MW |
| D. | 00 MW |
| Answer» E. | |
| 77. |
The time taken by the machine to attain 0.632 of its final steady temperature rise is called |
| A. | eating time constant |
| B. | ooling time constant |
| C. | ither (A) or (B) |
| D. | one of the above |
| Answer» B. ooling time constant | |
| 78. |
Systematic errors are~! |
| A. | instrumental errors |
| B. | environmental errors |
| C. | observational errors |
| D. | all of the above |
| Answer» E. | |
| 79. |
A practical formula for determining the thickness of insulation between low voltage and high voltage windings is%! |
| A. | 1 + 0.2 kV mm |
| B. | 2 + 0.5 kV mm |
| C. | 4 + 0.7 kV mm |
| D. | 5 + 0.9 kV mm |
| Answer» E. | |
| 80. |
In a Weston frequency meter, the magnetic axes of the two fixed coils are%! |
| A. | parallel |
| B. | perpendicular |
| Answer» C. | |
| 81. |
Which of the following methods is used for air cooling of turbo-alternators ?%! |
| A. | One sided axial ventilation |
| B. | Two sided axial ventilation |
| C. | Multiple inlet system |
| D. | All of the above |
| Answer» E. | |
| 82. |
The efficiency of a machine should be as ______ as possible to reduce the operating cost.%! |
| A. | high |
| B. | low |
| C. | either of the above |
| D. | none of the above |
| Answer» B. low | |
| 83. |
In D.C. machines the width of the duct is usually%! |
| A. | 4 mm |
| B. | 6 mm |
| C. | 8 mm |
| D. | 10 mm |
| Answer» E. | |
| 84. |
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 | |
| 85. |
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 | |
| 86. |
The flash point of transformer oil should be higher than%! |
| A. | 40°C |
| B. | 60°C |
| C. | 80°C |
| D. | 104°C |
| Answer» E. | |
| 87. |
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 | |
| 88. |
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 | |
| 89. |
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 | |
| 90. |
If the current in a capacitor leads the voltage by 80°, the loss angle of the capacitor is%! |
| A. | 10° |
| B. | 80° |
| C. | 120° |
| D. | 170° |
| Answer» B. 80¬¨‚àû | |
| 91. |
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. | |
| 92. |
An ohmmeter is a%! |
| A. | moving iron instrument |
| B. | moving coil instrument |
| C. | dynamometer instrument |
| D. | none of the above |
| Answer» C. dynamometer instrument | |
| 93. |
Which of the following is measured by using a vector voltmeter ?%! |
| A. | Amplifier gain and phase shift |
| B. | Filler transfer functions |
| C. | Complex insersion loss |
| D. | All of the above |
| Answer» E. | |
| 94. |
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 | |
| 95. |
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 | |
| 96. |
is usually used for brush rockers%! |
| A. | Mild steel |
| B. | Copper |
| C. | Aluminium |
| D. | Cast-iron |
| Answer» E. | |
| 97. |
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 | |
| 98. |
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 | |
| 99. |
*$_An ohmmeter is a? |
| A. | moving iron instrument |
| B. | moving coil instrument |
| C. | dynamometer instrument |
| D. | none of the above |
| Answer» C. dynamometer instrument | |
| 100. |
*$_Which of the following is measured by using a vector voltmeter ?? |
| A. | Amplifier gain and phase shift |
| B. | Filler transfer functions |
| C. | Complex insersion loss |
| D. | All of the above |
| Answer» E. | |