Home/Volume-2/Mine Lighting Volume-2 Mine Lighting Admin03/08/20240 22 Less than a minute Report a question What's wrong with this question? You cannot submit an empty report. Please add some details. 0% Mine Lighting Mine Lighting 1 / 39 1. The illumination at the pit bottom is? 20 to 40 lumens/sq.m 15 to 20 lumens/sq.m 40 to 60 lumens/sq.m None 2 / 39 2. The minimum average lumens/sq.ft of light at pit bottom is? 1.5 1.25 0.4 0.9 3 / 39 3. In order to avoid permanent sulfating of the plates in a lead acid battery the voltage of the lamp on usage must not be allowed to fall below? 1.8 V per cell 2.2 V per cell 4.4 V per cell 1.18 V per cell 4 / 39 4. The fire is extinct in the sealed off area if the oxygen percentage is? 12% 8% 6% 2% 5 / 39 5. At 2m distance the illumination from a light source of one candela is? 4 metre candles 2 metre candles 8 metre candles 0.25 candles 6 / 39 6. Where carbide lamps have to be used for safe working the air velocity should not exceed? 2.5 m/sec 2.5 m/min 5 m/sec 5 m/min 7 / 39 7. The battery in flame safety lamp can relight the lamp ? 600 times 700 times 400 times 300 times 8 / 39 8. The maximum battery voltage in flame safety lamp is? 2 3 4 5 9 / 39 9. The mesh size in flame safety lamp is? 30 20 10 5 10 / 39 10. The white washing is not done from the face up to ? 400 m 300 m 100 m 60 m 11 / 39 11. For depillaring area of gassy coal mines of II and III degree the amount duct of light in addition to cap lamp of individuals required to be provided is? A cluster of 10 to 12 cap lamps A cluster of 15-20 cap lamps 250 watt bulbs 4 or more None 12 / 39 12. An electric cap lamp with krypton bulb gives an amount of light? 15 lumens 20 lumens 30 lumens 50 lumens 13 / 39 13. The flame safety lamp used for accumulation test is? GL-5 GL-50 GL-60 None 14 / 39 14. The GL-60 flame safety lamp detects? CO CH4 CO2 Both 2 and 3 15 / 39 15. The acid used in cap lamp is? Sulphuric acid Hydrocloric acid Nitric acid None 16 / 39 16. The unit of illumination in S.I units is? Lumen Lux Candela None 17 / 39 17. The life of the lead acid battery is? 1 year 2 years 3 years 4 years 18 / 39 18. In the flame safety lamp should be discarded if the battery voltage is? Below 5 Above 5 Below 2.3 2.3 to 5 19 / 39 19. 1 lumen/sq.m is? Lumen Lux Candela None 20 / 39 20. An electric cap lamp of acid type gives? 1 V 2 V 4 V 6 V 21 / 39 21. In u/g mines the purpose of white washing is? To prevent coal dust explosion To prevent spontaneous heating To improve lighting Both 2 and 3 22 / 39 22. The minimum light required in longwall working face is? 10 lux 12 lux 2 lux 5 lux 23 / 39 23. The advantage of fluorescent lamp in underground is? More output Reduce glare Shall not produce shadow All of the above 24 / 39 24. In electric lighting the power cannot be used at a voltage exceeding ? 30 110 220 250 25 / 39 25. The minimum light required for reading and writing will be? 10 lumen/sq.m 10 lumen/sq.ft 1 lumen/sq.m 30 lumen/sq.m 26 / 39 26. The minimum oxygen percentage required for supporting human life? 12% 14% 16% 19% 27 / 39 27. Illumination is inversely proportional to ? Distance Square of distance Cube of distance None 28 / 39 28. The unit of light emitted by a light source is? Lumen Lux Candela None 29 / 39 29. The wire gauge in flame safety lamp should have a total heat radiation area of not less than? 400 sq.m 355 sq.m 250 sq.m 155 sq.m 30 / 39 30. The ability to cause a flame to spread away from the source of ignition is called? Index of explosibility Index of inflammability Index of ignitability Graham's index 31 / 39 31. The gas produced in the electric cap lamp is? Nitrogen Oxygen Hydrogen Both 2 and 3 32 / 39 32. It is recommended that the electric lamps should not be used within a distance of .... from the longwall face? 60 m 80 m 100 m 270 m 33 / 39 33. In the charged condition the specific gravity of the acid is ? 1.26 1.18 1.81 1.62 34 / 39 34. The percentage test will be conducted if the methane percentage is? 1 to 2 % 2 to 3 % 3 % or more Below 1 % 35 / 39 35. In the fully charged condition the active material in the positive plates is? Lead Antimony Silicon Lead peroxide 36 / 39 36. The life of the cap lamp in the pit is? 300 hours 400 hours 500 hours 600 hours 37 / 39 37. The minimum average lumens/sq.ft of light at roadways is? 1.5 1.25 0.4 0.9 38 / 39 38. The liquid used in GL-60 lamp is? Petrol Alcohol Diesel K-oil 39 / 39 39. The relative amount of luminous energy given by any source of light is? Illumination Lux Intensity of light Lumen Your score is The average score is 47% LinkedIn Facebook Twitter 0% Admin03/08/20240 22 Less than a minute
