MCQOPTIONS
Saved Bookmarks
MCQOPTIONS
This section includes 93 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. |
When a body reflects entire radiation incident on it, then it is known as |
| A. | white body |
| B. | grey body |
| C. | black body |
| D. | transparent body |
| Answer» B. grey body | |
| 52. |
Which of the following methods of heating is not dependent on the frequency of supply? |
| A. | induction heating |
| B. | dielectric heating |
| C. | electric resistance heating |
| D. | all of the above |
| Answer» D. all of the above | |
| 53. |
...... method has leading power factor |
| A. | resistance heating |
| B. | dielectric heating |
| C. | arc heating |
| D. | induction heating |
| Answer» C. arc heating | |
| 54. |
...... has the highest value of thermal conductivity. |
| A. | copper |
| B. | aluminium |
| C. | brass |
| D. | steel |
| Answer» B. aluminium | |
| 55. |
Which of the following is an advantages of heating by electricity? |
| A. | quicker operation |
| B. | higher efficiency |
| C. | absence of flue gases |
| D. | all of the above |
| Answer» C. absence of flue gases | |
| 56. |
The coreless induction furnace uses high-frequency electric supply in order to obtain high |
| A. | flux density |
| B. | eddy-current loss |
| C. | primary resistance |
| D. | power factor. |
| Answer» C. primary resistance | |
| 57. |
Which of the following furnace suffers from pinch effect? |
| A. | resistance furnace |
| B. | core type induction furnace |
| C. | coreless induction furnace |
| D. | vertical core type induction furnace. |
| Answer» C. coreless induction furnace | |
| 58. |
Which of the following heating method is based on the transformer principle ? |
| A. | resistance heating |
| B. | eddy-current heating |
| C. | induction heating |
| D. | dielectric heating. |
| Answer» D. dielectric heating. | |
| 59. |
Spot welding is used for |
| A. | thin metal sheets |
| B. | rough and irregular surfaces |
| C. | costings only |
| D. | thick sections |
| Answer» B. rough and irregular surfaces | |
| 60. |
In the indirect resistance heating method, heat is delivered to the charge |
| A. | direcly |
| B. | by radiation |
| C. | by convection |
| D. | both (b) and (c). |
| Answer» E. | |
| 61. |
Magnetic materials are heated with the help of |
| A. | hysteresis loss |
| B. | electric arc |
| C. | electric current |
| D. | radiation. |
| Answer» B. electric arc | |
| 62. |
Electric ovens using heating elements of........................... can produce temperatures up to 3000°C |
| A. | nickel |
| B. | graphite |
| C. | chromium |
| D. | iron. |
| Answer» C. chromium | |
| 63. |
Which of the following types of filters used in the air conditioning system is made of cloth that is discarded on getting dirty? |
| A. | viscous type filters |
| B. | dry filter |
| C. | spray washers |
| D. | electric precipitators |
| Answer» C. spray washers | |
| 64. |
When the heat stored in the body is                  the human body feels comfortable. |
| A. | zero |
| B. | infinite |
| C. | positive |
| D. | negative |
| Answer» B. infinite | |
| 65. |
Which of the following is true about the optimum effective temperature for human comfort? |
| A. | same in winter and summer |
| B. | not dependent on season |
| C. | lower in winter than in summer |
| D. | higher in winter than in summer |
| Answer» D. higher in winter than in summer | |
| 66. |
Centrifugal compressors are used to handle                volume of refrigerant. |
| A. | small |
| B. | medium |
| C. | large |
| D. | very large |
| Answer» D. very large | |
| 67. |
Which of the following cooling towers possess maximum heat transfer from air to water? |
| A. | natural draft |
| B. | mechanical draft |
| C. | natural and mechanical draft |
| D. | atmospheric draft |
| Answer» C. natural and mechanical draft | |
| 68. |
Which of the following is the condition to use two compressors in the refrigeration system? |
| A. | the desired temperature is 3°c |
| B. | the desired temperature is -3°c |
| C. | the desired temperature is -50°c |
| D. | the desired temperature is -5°c |
| Answer» D. the desired temperature is -5°c | |
| 69. |
                 is widely used in large industrial plants such as cold storages and ice plants as per the cost basis. |
| A. | r – 40 |
| B. | r – 717 |
| C. | r – 744 |
| D. | r – 764 |
| Answer» C. r – 744 | |
| 70. |
Where is the reciprocating compressor mostly suitable? |
| A. | small displacements and low condensing pressures |
| B. | small displacements and high condensing pressures |
| C. | large displacements and low condensing pressures |
| D. | large displacements and high condensing pressures |
| Answer» C. large displacements and low condensing pressures | |
| 71. |
In the presence of which of the following, Sulphur dioxide becomes corrosive? |
| A. | r – 12 |
| B. | ammonia |
| C. | water |
| D. | carbon dioxide |
| Answer» D. carbon dioxide | |
| 72. |
From the following refrigerants, which is one of the most stable refrigerants? |
| A. | ammonia |
| B. | r – 12 |
| C. | carbon dioxide |
| D. | sulphur dioxide |
| Answer» E. | |
| 73. |
Which one of the following inorganic refrigerants is often used? |
| A. | nh3 |
| B. | co2 |
| C. | h2o |
| D. | so2 |
| Answer» B. co2 | |
| 74. |
The refrigerants which are first cooled by                    refrigerants and then used for cooling purposes are known as                        refrigerants. |
| A. | secondary, primary |
| B. | primary, secondary |
| C. | tertiary, primary |
| D. | secondary, tertiary |
| Answer» C. tertiary, primary | |
| 75. |
Which of the following is not the type of refrigerant? |
| A. | organic refrigerants |
| B. | inorganic refrigerants |
| C. | azeotrope refrigerants |
| D. | halo-helium refrigerants |
| Answer» E. | |
| 76. |
Which gas can be filled in GLS lamps? |
| A. | oxygen |
| B. | carbon dioxide |
| C. | xenon |
| D. | any inert gas |
| Answer» E. | |
| 77. |
For normal reading the illumination level required is around |
| A. | 20-40 lumens/m2 |
| B. | 60-100 lumens/m2 |
| C. | 200-300 lumens/m2 |
| D. | 400-500 lumens/m2 |
| Answer» C. 200-300 lumens/m2 | |
| 78. |
...... is a cold cathode lamp. |
| A. | fluorescent lamp |
| B. | neon lamp |
| C. | mercury vapour lamp |
| D. | sodium vapour lamp |
| Answer» C. mercury vapour lamp | |
| 79. |
The flicker effect of fluorescent lamps is more pronounced at |
| A. | lower frequencies |
| B. | higher frequencies |
| C. | lower voltages |
| D. | higher voltages |
| Answer» B. higher frequencies | |
| 80. |
For the same lumen output, the running cost of the fluorescent lamp is |
| A. | equal to that of filament lamp |
| B. | less than that of filament lamp |
| C. | more than that of filament lamp |
| D. | any of the above |
| Answer» C. more than that of filament lamp | |
| 81. |
On which of the following factors dies the depreciation or maintenance factor depend? |
| A. | lamp cleaning schedule |
| B. | ageing of the lamp |
| C. | type of work carried out at the premises |
| D. | all of the above factors |
| Answer» E. | |
| 82. |
Which of the following lamps is the cheapest for the same wattage? |
| A. | fluorescent tube |
| B. | mercury vapour lamp |
| C. | gls lamp |
| D. | sodium vapour lamp |
| Answer» D. sodium vapour lamp | |
| 83. |
The filament of a GLS lamp is made of |
| A. | tungsten |
| B. | copper |
| C. | carbon |
| D. | aluminium |
| Answer» B. copper | |
| 84. |
Filament lamps operate normally at a power factor of |
| A. | 0.5 lagging |
| B. | 0.8 lagging |
| C. | unity |
| D. | 0.8 leading |
| Answer» D. 0.8 leading | |
| 85. |
The unit of luminous flux is . |
| A. | watt/m2 |
| B. | lumen |
| C. | lumen/m2 |
| D. | watt |
| Answer» C. lumen/m2 | |
| 86. |
A solid angle is expressed in terms of |
| A. | radians/metre |
| B. | radians |
| C. | steradians |
| D. | degrees |
| Answer» D. degrees | |
| 87. |
Illumination of one lumen per sq. metre is called |
| A. | lumen metre |
| B. | lux |
| C. | foot candle |
| D. | candela |
| Answer» C. foot candle | |
| 88. |
Colour of light depends upon |
| A. | frequency |
| B. | wave length |
| C. | both (a) and (b) |
| D. | speed of light |
| Answer» D. speed of light | |
| 89. |
Candela is the unit of which of the following? |
| A. | wavelength |
| B. | luminous intensity |
| C. | luminous flux |
| D. | frequency |
| Answer» C. luminous flux | |
| 90. |
Floodlighting is NOT used for purposes. |
| A. | reading |
| B. | aesthetic |
| C. | advertising |
| D. | industrial. |
| Answer» B. aesthetic | |
| 91. |
Which of the following instruments is used for the comparison of candle powers of different sources? |
| A. | radiometer |
| B. | bunsen meter |
| C. | photometer |
| D. | candle meter |
| Answer» D. candle meter | |
| 92. |
The illumination at various points on a horizontal surface illuminated by the same source varies as |
| A. | cos3θ |
| B. | cos θ |
| C. | 1/r2 |
| D. | cos2θ. |
| Answer» B. cos θ | |
| 93. |
Which of the following lamp has minimum initial cost of installation but maximum running cost ? |
| A. | incandescent |
| B. | fluorescent |
| C. | mercury vapour |
| D. | sodium vapour. |
| Answer» B. fluorescent | |