Sunlight
(A) Helps growth of bacterias
(B) Impedes growth of algae
(C) Increases dissolved oxygen content
(D) Reduces turb
Description : Presence of carbonaceous matter in the sewage (A) Causes reduction in its dissolved oxygen content thereby endangering the life of aquatic creatures (B) Reduces sulphate ions to sulphides causing obnoxious ... quantity of chlorine used for its purification (D) All (A), (B) and (C)
Last Answer : (D) All (A), (B) and (C)
Description : The amount of oxygen consumed by the aerobic bacterias which cause the aerobic biological decomposition of sewage, is known A. Bio-Chemical Oxygen Demand (B.O.D.) B. Dissolved Oxygen (D.O.) C. Chemical Oxygen Demand (C.O.D.) D. None of these
Last Answer : ANS: B
Description : Pick out the correct statement. (A) Oxygen content decreases from lignite to bituminous coal as the coalification increases (B) The less the oxygen content, better is the coal, as it reduces the calorific value (C ... capacity of coal increases and the caking power decreases (D) All (A), (B) and (C)
Description : Bacterias which can survive with or without free oxygen, are known (A) Aerobic bacterias (B) Anaerobic bacterias (C) Facultative bacterias (D) None of these
Last Answer : (C) Facultative bacterias
Description : The bacterias which may survive with or without free oxygen, are called (A) Aerobic bacterias (B) Anaerobic bacterias (C) Facultative bacteria's (D) None of these
Last Answer : (C) Facultative bacteria's
Description : The bacterias which require free oxygen for their survival, are called (A) Aerobic bacterias (B) Anaerobic bacterias (C) Facultative bacteria (D) None of these
Last Answer : (A) Aerobic bacterias
Description : Which one of the following statements is wrong? (a) Algae increase the level of dissolved oxygen in the immediate environment. (b) Algin is obtained from red algae, and carrageenan from brown ... Agar-agar is obtained from Gelidium and Gracilaria. (d) Laminaria and Sargassum are used as food.
Last Answer : (b) Algin is obtained from red algae, and carrageenan from brown algae
Description : Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by (A) Natural aeration of water stream (B) Photosynthetic action of algae (C) Both (A) & (B) (D) Neither (A) nor (B)
Last Answer : (C) Both (A) & (B)
Description : Chlorination of water does not remove (A) Ammonia content (B) B.O.D. (C) Organic matter content (D) Dissolved oxygen
Last Answer : (D) Dissolved oxygen
Description : Increase in the moisture content in concrete (A) Reduces the strength (B) Increases the strength (C) Does not change the strength (D) All of the above
Last Answer : Answer: Option A
Description : In the illustration, if one of the devices labeled 'TURB' should fail the ___________. EL-0003 A. device labeled 'EXC' will drive the alternator B. device labeled 'BKR' for that ... -alternator D. emergency generator should automatically start and be placed on line to supply emergency load centers
Last Answer : Answer: B
Description : The following is true about actions of ethylalcohol: A. It exerts anticonvulsant action followed by lowering of seizure threshold B. It lowers pain threshold C. It increases confidence and reduces number of errors D. It increases heat production and helps to keep warm in cold weather
Last Answer : A. It exerts anticonvulsant action followed by lowering of seizure threshold
Description : The Brake Horse power of the motor (efficiency 60%) required for a pump of capacity 0.075 cumec for a total lift of 12 m, is A. 10 B. 15 C. 20 D. 25 Q No: 44 Aerobic bacterias A. ... presence of free oxygen B. Consume organic matter as their food C. Oxidise organic matter in sewage D. All the above
Last Answer : ANS: D
Description : Dilution method of disposing of sewage, is not preferred to A. When sewage is fresh B. When diluting water has high dissolved oxygen content C. When diluting water is used for water supply near the point of sewage disposed D. When the diluting water is having flow currents
Last Answer : ANS: C
Description : Dissolved oxygen content in river water is around __________ ppm. (A) 5 (B) 100 (C) 250 (D) 500
Last Answer : (A) 5
Description : Pick out the wrong statement. (A) Caustic embrittlement of boiler's metallic parts is caused by highconcentration of caustic soda in boiler feed water (B) Cooling and freezing of water kills the ... goes on decreasing (D) Dissolved oxygen content in high pressure boiler feed water should be nil
Last Answer : (B) Cooling and freezing of water kills the bacteria present in it
Description : . Presence of iron and manganese in water causes (A) Reduction in its dissolved oxygen content (B) Discoloration of bathroom fixtures (C) Temporary hardness (D) None of these
Last Answer : (B) Discoloration of bathroom fixtures
Description : Deaeration of high pressure boiler feed water is done to reduce (A) Foaming from boilers (B) Its dissolved oxygen content (C) Its silica content (D) Caustic embrittlement
Last Answer : (B) Its dissolved oxygen content
Description : The detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of __________ of water. (A) Dissolved oxygen content (B) Biological oxygen demand (C) Vapor pressure (D) All (A), (B) and (C)
Last Answer : (A) Dissolved oxygen content
Description : For existence of aquatic life in water, the dissolved oxygen content in it, should not be less than __________ ppm. (A) 10000 (B) 5 (C) 500 (D) 1000
Last Answer : (B) 5
Description : The best guide to judge the general quality of water is the measurement of its (A) pH value (B) Electrical conductivity (C) Turbidity (D) Dissolved oxygen content
Last Answer : (B) Electrical conductivity
Description : True statements about aldosterone include: a. it increases the amount of Na+-K+ ATPase in the target cells b. it reduces the sodium content of the sweat c. it increases the acidity of urine d. all above
Last Answer : all above
Description : Increase in ash content of blast furnace coke (A) Reduces its consumption in the furnace (B) Increases its consumption in the furnace (C) Does not affect its consumption in the furnace (D) Decreases its hardness and abrasion resistance
Last Answer : (B) Increases its consumption in the furnace
Description : Washing of coal (A) Reduces its sulphur and ash content (B) Controls its ash fusibility and increases its calorific value (C) Improves its coking properties (D) All (A), (B) and (C)
Description : High sulphur content in a fuel __________ of the flue gases. (A) Decreases the dew point (B) Increases the dew point (C) Reduces the combustion efficiency by limiting the permissible temperature reduction (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : Chemical coagulation of drinking water, is done (A) To settle suspended materials (B) To increase rate of settlement of suspended materials (C) To remove the bacterias (D) None of these
Last Answer : (B) To increase rate of settlement of suspended materials
Description : Pick up the incorrect statement from the following: (A) Water disinfected with ozone is free from any odour (B) Ozone removes bacterias as well as colour and odour (C) Ozonized water becomes tasteless (D) None of these
Last Answer : (C) Ozonized water becomes tasteless
Description : Non-pathogenic bacterias cause the following water borne disease, (A) Cholera (B) Typhoid (C) Infections hepatitis (D) None of these
Last Answer : (D) None of these
Description : Surface water may (A) Contain large amount of impurities (B) Be contaminated by impurities (C) Contain disease producing bacterias (D) All the above
Last Answer : (D) All the above
Description : Disinfection of drinking water, is done to remove (A) Odour (B) Bacterias (C) Turbidity (D) Colour
Last Answer : (B) Bacterias
Description : Disinfection of drinking water is done to remove (A) Turbidity (B) Odour (C) Colour (D) Bacterias
Last Answer : (D) Bacterias
Description : Efficiency of removing bacterias from raw water by a slow sand filter, is (A) 80% to 81% (B) 85% to 86% (C) 90% to 97% (D) 98% to 99%
Last Answer : (D) 98% to 99%
Description : Hard water for public water supply is discarded because (A) It consumes more soap (B) It contains lot of turbidity (C) It contains pathogenic bacterias (D) It possesses bad taste and odour
Last Answer : (A) It consumes more soap
Description : Aeration of water is done to remove (A) Odour (B) Colour (C) Bacterias (D) Turbidity
Last Answer : (A) Odour
Description : Pick up the correct statement from the following: (A) Due to boiling, the bacterias present in water can be destroyed (B) Lime may be used for softening hard water (C) Excess lime when added to water, raises the pH value of water (D) All the above
Description : Disinfection of water with ozone is not good because (A) It vanishes before water reaches the consumers (B) It removes the colour, taste and odour from water as bacterias (C) It adds taste to the water (D) It is more efficient than chlorine in killing bacterias
Last Answer : (D) It is more efficient than chlorine in killing bacterias
Description : Pick up the correct statement from the following: (A) Lime may be used to soften the hard water (B) Excessive use of lime may kill the bacterias (C) Excessive lime when added to water, raises its pH value (D) All the above
Description : Which one of the following tests employs Ethylene Diamine Tetra Acetic Acid as a titrating agent? (a) Chlorides (b) Dissolved oxygen (c) Hardness (d) Residual chlorine
Last Answer : (c) Hardness
Description : Pick up the correct statement from the following: (A) The dry density reduces by addition of water after attaining optimum moisture content (B) The line joining the peak of three moisture content graphs ... be compacted to a very high density as compared to fine grained soils (D) All the above
Last Answer : Answer: Option D
Description : Pick up the correct statement from the following: (A) A highly absorptive aggregate reduces the workability of concrete considerably (B) The specific gravity of aggregate is important for the determination ... and porosity of an aggregate influence the property of the concrete (D) All the above
Description : Why is water not suitable for putting out a petrol fire? (1) The oxygen content of water is isolated by petrol and thus it helps in burning (2) Petrol is too inflammable to be extinguished by ... very low (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns
Last Answer : (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns Explanation: Water is not effective on petrol fire because it has higher density than ... while petrol stays afloat and keeps burning. Petrochemical fires are nearly always extinguished with chemical foam.
Last Answer : (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns Explanation: Water is not effective on petrol fire because it has higher density than petrol as a ... extinguished with chemical foam which forms a blanket over the flames and cuts off the oxygen supply.
Description : Why is water not suitable for putting out a petrol fire ? (1) The oxygen content of water is isolated by petrol and thus it helps in burning (2) Petrol is too inflammable to be extinguished by ... very low (4) Water, being heavy, slips below petrol which thus remains in contact with air and burns
Last Answer : Water, being heavy, slips below petrol which thus remains in contact with air and burns
Description : Consider the following statements: Sinking of an intermediate support of a continuous beam 1. Reduces the negative moment at support. 2. Increases the negative moment at support. 3. Reduces the positive moment at ... 1 and 3 are correct (C) 2 and 3 are correct (D) 2 and 4 are correct
Last Answer : (A) 1 and 4 are correct
Description : The part radiation due to scattered/diffused radiation entering the field of view of a remote sensor other than that from the required target, (A) Reduces the contrast of the image and also its ... (C) Increases both the contrast and sharpness (D) Reduces the contrast but increases the sharpnes
Description : Select the correct statement. (A) A meander increases the river length but a cut off reduces the river length (B) A cut-off increases the river length but a meander reduces the river length ( ... meander and cut-off increase the river length (D) Both meander and cut-off decrease the river length
Description : Sinking of an intermediate support of a continuous beam (i) Reduces the negative moment at support (ii) Increases the negative moment at support (iii) Reduces the positive moment at center of span (iv) Increases the positive moment ... (B) (i) and (iv) (C) (ii) and (iii) (D) (ii) and (iv)
Last Answer : Answer: Option B
Description : As compared to ordinary Portland cement, use of pozzolana cement (A) Reduces workability (B) Increases bleeding (C) Increases shrinkage (D) Increases strength
Last Answer : Answer: Option C
Description : Pick up the incorrect statement from the following: (A) With passage of time, the strength of cement increases (B) With passage of time, the strength of cement decreases (C) After a ... of cement reduces to 50% (D) The concrete made with storage deteriorated cement, gains strength with time
Description : Due to circumferential action of the spiral in a spirally reinforced column (A) Capacity of column is decreased (B) Ductility of column reduces (C) Capacity of column is decreased but ductility of column increases (D) Both the capacity of column and ductility of column increase