MCQOPTIONS
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MCQOPTIONS
This section includes 37 Mcqs, each offering curated multiple-choice questions to sharpen your Utilization Of Electrical Energy knowledge and support exam preparation. Choose a topic below to get started.
| 1. |
A 200 CP lamp is hung 4 metres above the centre of a circular area of diameter 5 m. The illumination at the centre of the area will be: |
| A. | 12.73 lux |
| B. | 9.73 lux |
| C. | 12.5 lux |
| D. | 15.92 lux |
| Answer» C. 12.5 lux | |
| 2. |
A room 12 m × 12 m is lit by 10 lamps to a fairly uniform illumination of 100 lm/m2. Calculate the utilization coefficient of the room given that the output of each lamp is 1600 lumens. |
| A. | 0.5 |
| B. | 0.3 |
| C. | 0.9 |
| D. | 0.4 |
| Answer» D. 0.4 | |
| 3. |
Illumination level in public area should be around |
| A. | 100 lux |
| B. | 50 lux |
| C. | 200 lux |
| D. | 1000 lux |
| Answer» C. 200 lux | |
| 4. |
A factory hall of 80 m × 25 m is required to be illuminated with an illumination of 15 candle per square meter using 120 lamps each having an efficiency of 15 lumens per watts. Assuming an utilization factor and depreciation factor of 0.4 and 0.7 respectively, the estimated wattage of lamps is ______. |
| A. | 200 W |
| B. | 60 W |
| C. | 100 W |
| D. | 40 W |
| Answer» C. 100 W | |
| 5. |
If dΦ is the luminous flux incident normally on an area dA, then Illuminance is given as: |
| A. | dΦ - dA |
| B. | Φ × A |
| C. | \(\frac{{dA}}{{d{\rm{\Phi }}}}\) |
| D. | \(\frac{{d{\rm{\Phi }}}}{{dA}}\) |
| Answer» E. | |
| 6. |
A sodium vapour lamp consists of an inner bulb of special glass containing the sodium and inert gas at a pressure of ________ Hg. |
| A. | 1.5 mm |
| B. | 1.8 mm |
| C. | 2.5 mm |
| D. | 3.5 mm |
| Answer» B. 1.8 mm | |
| 7. |
A fluorescent tube of 20 W has a luminous flux of: |
| A. | 325 lumens |
| B. | 14 lumens |
| C. | 950 lumens |
| D. | 75 lumens |
| Answer» D. 75 lumens | |
| 8. |
For precision work the illumination level required is of the order of |
| A. | 500 to 1000 lumens/m2 |
| B. | 50 to 100 lumens/m2 |
| C. | 200 to 400 lumens/m2 |
| D. | 10 to 25 lumens/m2 |
| Answer» B. 50 to 100 lumens/m2 | |
| 9. |
Absorptivity of a perfect black body is: |
| A. | Zero |
| B. | 0 - 1 |
| C. | 1 |
| D. | Cannot be determined |
| Answer» D. Cannot be determined | |
| 10. |
______ is a form of electromagnetic energy radiated from a body which is capable of being perceived by the human eye. |
| A. | Vibration |
| B. | Heat |
| C. | Current |
| D. | Light |
| Answer» E. | |
| 11. |
Halogen lamps have the advantage(s) of: |
| A. | Reduced dimensions of the lamp |
| B. | Better colour rendition and longer life (about 2,000 hr) |
| C. | High operating temperature with increased luminous efficiency |
| D. | All of the above |
| Answer» E. | |
| 12. |
Radiant efficiency of a luminous source depends on on_____. |
| A. | Shape of the source |
| B. | Temperature of the source |
| C. | Wave length of light rays |
| D. | All options are correct |
| Answer» C. Wave length of light rays | |
| 13. |
A/an ______ system utilises luminaries which send most of the light downwards directly on the working plane but a considerable amount reaches the ceilings and walls also. |
| A. | semi-indirect |
| B. | direct |
| C. | semi-direct |
| D. | indirect |
| Answer» D. indirect | |
| 14. |
For indoor lighting the range of space : height is _____. |
| A. | 3 : 4 |
| B. | 5 : 6 |
| C. | 1 : 2 |
| D. | 2 : 3 |
| Answer» D. 2 : 3 | |
| 15. |
Lamp efficiency is measured in ________ |
| A. | lumen/watt |
| B. | lumen/lux |
| C. | candela/watt |
| D. | lux/watt |
| Answer» B. lumen/lux | |
| 16. |
Glare is reduced by |
| A. | Using diffusers |
| B. | Increases the height of lamp |
| C. | Using reflectors to cut off the light at certain angle |
| D. | All of the above |
| Answer» E. | |
| 17. |
In which of the following lighting systems, more than 90% of the total light flux is made to fall directly on the working plane with the help of deep reflectors? |
| A. | Direct lighting |
| B. | Indirect lighting |
| C. | General diffusing lighting |
| D. | Semi-indirect lighting |
| Answer» B. Indirect lighting | |
| 18. |
1 foot candle (ftcd) = |
| A. | 1 lumen/sq.ft |
| B. | 0.1 lumen/sq.ft |
| C. | 0.001 lumen/sq.ft |
| D. | 10 lumen/sq.ft |
| Answer» B. 0.1 lumen/sq.ft | |
| 19. |
Lighting in restaurants and malls is an example of _______. |
| A. | industrial load |
| B. | domestic load |
| C. | agriculture load |
| D. | commercial load |
| Answer» E. | |
| 20. |
Lumen/watt is the unit of_______. |
| A. | Light flux |
| B. | Luminous intensity |
| C. | Brightness |
| D. | Luminous efficiency |
| Answer» E. | |
| 21. |
One lumen per square metre is termed as: |
| A. | Candle power |
| B. | MHCP |
| C. | One lux |
| D. | MSCP |
| Answer» D. MSCP | |
| 22. |
In which of the following lighting schemes is 90% to 100% of total light flux thrown upward to the ceiling for diffused reflection? |
| A. | Semi-direct lighting |
| B. | Semi-indirect lighting |
| C. | Indirect lighting |
| D. | Direct lighting |
| Answer» D. Direct lighting | |
| 23. |
______ is the mean of candle powers in all directions in all places. |
| A. | Mean All Surfaces Candle Power |
| B. | Mean Vertical Candle Power |
| C. | Mean Surface Candle Power |
| D. | Mean Spherical Candle Power |
| Answer» E. | |
| 24. |
A light source having an intensity of 400 candle power is fitted with a reflector so that it directs 70 percent of its light along a beam having a divergence angle of 5 degrees. Total flux emitted along the beam is: |
| A. | 1600 / π |
| B. | 1120 π |
| C. | 1600 π |
| D. | 1120 / π |
| Answer» C. 1600 π | |
| 25. |
A lamp takes 5 A at 250 V and emits 8000 lumens. Its MSCP is: |
| A. | 2000 π |
| B. | 1400 π |
| C. | 2000 / π |
| D. | 1250 π |
| Answer» D. 1250 π | |
| 26. |
If the candle power is 45cd, then how much flux will be emitted by this source? |
| A. | 565.2 lumens |
| B. | 764 lumens |
| C. | 0.00725 lumens |
| D. | 9.20 lumens |
| Answer» B. 764 lumens | |
| 27. |
1 lux = _______ |
| A. | 0.1 lumens / m2 |
| B. | 1 lumens / cm2 |
| C. | 1 lumens / m2 |
| D. | 0.1 lumens / cm2 |
| Answer» D. 0.1 lumens / cm2 | |
| 28. |
Candela is a unit of __________. |
| A. | Luminous intensity |
| B. | Luminous Flux |
| C. | Wavelength |
| D. | Frequency |
| Answer» B. Luminous Flux | |
| 29. |
Inverse square law and Lambert’s cosine law are laws pertaining to which of the following parameters? |
| A. | Electricity |
| B. | Resistance |
| C. | Illumination |
| D. | Magnetism |
| Answer» D. Magnetism | |
| 30. |
In illumination, what is lamp efficiency represented in: |
| A. | Lumen-watt |
| B. | Total flux in lumen/2π |
| C. | Lumens/watt |
| D. | Total flux in lumen/4π |
| Answer» D. Total flux in lumen/4π | |
| 31. |
Light energy radiated per second from a luminous body is known as: |
| A. | luminous flux |
| B. | watt |
| C. | candela |
| D. | lumen |
| Answer» B. watt | |
| 32. |
Illumination is measured using which one of the following. |
| A. | Millivolt meter |
| B. | Stroboscope |
| C. | Lux meter |
| D. | PH meter |
| Answer» D. PH meter | |
| 33. |
A photocell is illuminated by a small bright source placed 1 m away. When the same source of light is placed two meters away, the electrons emitted by the photocathode _____. |
| A. | each carry one quarter of their previous energy |
| B. | each carry one quarter of their previous moments |
| C. | are half as numerous |
| D. | are one-quarter as numerous |
| Answer» E. | |
| 34. |
______ is the angle generated by a surface passing through a point in space and a periphery of the area. |
| A. | Radian |
| B. | Solid angle |
| C. | Degree |
| D. | Angle of incidence |
| Answer» C. Degree | |
| 35. |
\(\frac{{reflected\;light}}{{incident\;light}} = \_\_\_\_\_\_\_\_\) |
| A. | waste light factor |
| B. | the absorption factor |
| C. | reflection factor |
| D. | maintenance factor |
| Answer» D. maintenance factor | |
| 36. |
In the electric discharge lamps, the light is produced by: |
| A. | The magnetic effect of current |
| B. | The heating effect of current |
| C. | Cathode ray emission |
| D. | The ionization in a gas or vapour |
| Answer» E. | |
| 37. |
A room measuring 12 × 20 ft is illuminated by 10 lamps rated 100 W each with an efficiency of 12 lumens/watt. Assuming a depreciation factor of 1.5 and coefficient of utilization as 0.5, the illumination at the plane of the room is |
| A. | 23.48 lumens/ft2 |
| B. | 16.67 lumens/ft2 |
| C. | 48.36 lumens/ft2 |
| D. | 34.54 lumens/ft2 |
| Answer» C. 48.36 lumens/ft2 | |