Which one of the following statements regarding septic tanks is wrong? A. A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided B. The outlet invert level is kept 5 to 7.5 cm below the inlet invert level C. The minimum width of septic level is 90 cm D. The depth of tank is kept equal to its width

Which one of the following statements regarding septic tanks is wrong? A. A gap of 7.5 cm between the bottom of the covering slab and the top level of scum is provided B. The outlet invert level is kept 5 to 7.5 cm below the inlet invert level C. The minimum width of septic level is 90 cm D. The depth of tank is kept equal to its width
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ANS: D
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In septic tanks, A. Free board of 0.3 m may be provided B. The baffles or tees are extended up to top level of scum C. The clear space between the baffle top and covering slab is about 7.5 cm D. All the above

Description : In septic tanks, A. Free board of 0.3 m may be provided B. The baffles or tees are extended up to top level of scum C. The clear space between the baffle top and covering slab is about 7.5 cm D. All the above

Last Answer : ANS: D

Assertion A.: A free board of 0.3 m is provided above the top sewage line in septic tanks. Reason (R): It helps to accommodate the scum in the septic tank. A. Both A and R is true and R is the correct explanation of A B. Both A and R is true but R is not a correct explanation of A C. A is true but R is false D. A is false but R is true

Description : Assertion A.: A free board of 0.3 m is provided above the top sewage line in septic tanks. Reason (R): It helps to accommodate the scum in the septic tank. A. Both A and R is true and R is the correct ... is not a correct explanation of A C. A is true but R is false D. A is false but R is true

Last Answer : ANS: A

The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope A. 1 in 5 B. 1 in 10 C. 1 in 15 D. 1 in 20

Description : The bottom of the sewage inlet chamber of septic tanks, is provided an outward slope A. 1 in 5 B. 1 in 10 C. 1 in 15 D. 1 in 20

Last Answer : ANS: B

For a continuous flow type of sedimentation tanks A. Width of the tank is normally kept about 6 m B. Length of the tank is normally kept 4 to 5 times the width C. Maximum horizontal flow velocity is limited to 0.3 m/minute D. All the above

Description : For a continuous flow type of sedimentation tanks A. Width of the tank is normally kept about 6 m B. Length of the tank is normally kept 4 to 5 times the width C. Maximum horizontal flow velocity is limited to 0.3 m/minute D. All the above

Last Answer : ANS: D

The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is A. 204 cu.m B. 208 cu.m C. 212 cu.m D. 216 cu.m

Description : The dimensions of a rectangular settling tank are: length 24 m, width 6 m and depth 3 m. If 2 hour detention period for tanks is recommended, the rate of flow of sewage per hour, is A. 204 cu.m B. 208 cu.m C. 212 cu.m D. 216 cu.m

Last Answer : ANS: D

Drop manholes at the junctions of sewer lines, are provided if A. Invert level of a branch sewer is more than 60 cm that of the main sewer B. Sewer line runs along a main road C. Ordinary manhole cannot be built D. Two sewer lines intersect

Description : Drop manholes at the junctions of sewer lines, are provided if A. Invert level of a branch sewer is more than 60 cm that of the main sewer B. Sewer line runs along a main road C. Ordinary manhole cannot be built D. Two sewer lines intersect

Last Answer : ANS: A

The clarigesters are A. Circular septic tanks B. Rectangular septic tanks C. Circular Imhoff double tanks with bottom hoppers D. Circular Imhoff double storey tanks without bottom hoppers

Description : The clarigesters are A. Circular septic tanks B. Rectangular septic tanks C. Circular Imhoff double tanks with bottom hoppers D. Circular Imhoff double storey tanks without bottom hoppers

Last Answer : ANS: D

Pick up the incorrect statement from the following: A. Septic tanks are horizontal continuous flow type of sedimentation tanks B. Septic tanks are generally provided a detention period of 12 to 36 hours C. Septic tanks are completely covered and high vent shafts are provided for the escape of foul gases D. None of these

Description : Pick up the incorrect statement from the following: A. Septic tanks are horizontal continuous flow type of sedimentation tanks B. Septic tanks are generally provided a detention period of 12 to 36 hours C ... covered and high vent shafts are provided for the escape of foul gases D. None of these

Last Answer : ANS: D

The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is A. 100 cm B. 110 cm C. 120 cm D. 150 cm

Description : The sewage discharge in a detritus tank of a treatment plant is 576 litres/sec with flow velocity of 0.2 m/sec. If the ratio of width to depth is 2, the depth is A. 100 cm B. 110 cm C. 120 cm D. 150 cm

Last Answer : ANS: C

The minimum width of a septic tank is taken (A) 70 cm (B) 75 cm (C) 80 cm (D) 90 c

Description : The minimum width of a septic tank is taken (A) 70 cm (B) 75 cm (C) 80 cm (D) 90 c

Last Answer : (B) 75 cm

The maximum depth of sedimentation tanks, is kept A. 3 m B. 3.5 m C. 4 m D. 4.5 m

Description : The maximum depth of sedimentation tanks, is kept A. 3 m B. 3.5 m C. 4 m D. 4.5 m

Last Answer : ANS: A

The digested sludge from septic tanks, is removed after a maximum period of A. 3 years B. 3.5 years C. 4 years D. 5 years

Description : The digested sludge from septic tanks, is removed after a maximum period of A. 3 years B. 3.5 years C. 4 years D. 5 years

Last Answer : ANS: A

In septic tanks, decomposition of organic bacteria, is done by A. Anaerobic bacteria B. Aerobic bacteria C. Both types of bacterias D. None of these

Description : In septic tanks, decomposition of organic bacteria, is done by A. Anaerobic bacteria B. Aerobic bacteria C. Both types of bacterias D. None of these

Last Answer : ANS: A

The sewage treatment in septic tanks is due to A. Anaerobic decomposition B. Aerobic decomposition C. Parasitic decomposition D. None of these

Description : The sewage treatment in septic tanks is due to A. Anaerobic decomposition B. Aerobic decomposition C. Parasitic decomposition D. None of these

Last Answer : ANS: A

Antisyphonage pipe is fitted A. At the end of septic tanks B. On manholes C. With a W.C. trap D. At the beginning of sewer line

Description : Antisyphonage pipe is fitted A. At the end of septic tanks B. On manholes C. With a W.C. trap D. At the beginning of sewer line

Last Answer : ANS: C

The rate of accumulation of sludge in septic tanks is recommended as A. 30 litres/person/year B. 25 litres/person/year C. 30 litres/person/month D. 25 litres/person/month

Description : The rate of accumulation of sludge in septic tanks is recommended as A. 30 litres/person/year B. 25 litres/person/year C. 30 litres/person/month D. 25 litres/person/month

Last Answer : ANS: A

In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is A. Q/(B × D) B. Q/(L × D) C. Q/L D. Q/(B × L)

Description : In a sedimentation tank (length L, width B, depth D) the settling velocity of a particle for a discharge Q, is A. Q/(B × D) B. Q/(L × D) C. Q/L D. Q/(B × L)

Last Answer : ANS: D

A low mold board with gradual twist that completely invert the furrow slice with a minimum of breakup, thus covering vegetative matter thoroughly is called a. Stubble bottom b. sod bottom c. salted mould board d. general purpose bottom

Description : A low mold board with gradual twist that completely invert the furrow slice with a minimum of breakup, thus covering vegetative matter thoroughly is called a. Stubble bottom b. sod bottom c. salted mould board d. general purpose bottom

Last Answer : b. sod bottom

24 pumps are connected to a tank. Some of them are inlet pumps and the others are outlet pumps. Each of the inlet pumps an fill the tank in 16hours and each of the outlet pumps can empty the tank completely in 12hours. If all the pumps are kept open, the empty tank gets filled in 48 hours. How many inlet pumps are there? A) 16 B) 18 C) 17 D) 14

Description : 24 pumps are connected to a tank. Some of them are inlet pumps and the others are outlet pumps. Each of the inlet pumps an fill the tank in 16hours and each of the outlet pumps can empty the tank completely in ... gets filled in 48 hours. How many inlet pumps are there? A) 16 B) 18 C) 17 D) 14

Last Answer : D (x/16)-[(24-x)/12] = 1/48 x/16-24/48+x/12=1/48 (3+4)x/48=97/48 7x/48=97/48 7x=97 X=14

The detention time (t) of a settling tank, may be defined as the time required for A. A particle to travel along its length B. A particle to travel from top surface to bottom sludge zone C. The flow of sewage to fill the tank D. None of these

Description : The detention time (t) of a settling tank, may be defined as the time required for A. A particle to travel along its length B. A particle to travel from top surface to bottom sludge zone C. The flow of sewage to fill the tank D. None of these

Last Answer : ANS: C

The effluent of a septic tank is A. Fit for discharge into any open drain B. Foul and contains dissolved and suspended solids C. As good as that from a complete treatment D. None of these

Description : The effluent of a septic tank is A. Fit for discharge into any open drain B. Foul and contains dissolved and suspended solids C. As good as that from a complete treatment D. None of these

Last Answer : ANS: A

Bottom openings 15 cm × 15 cm in the standing baffle wall are provided A. 15 cm c/c B. 22.5 cm c/c C. 30 cm c/c D. 50 cm c/c

Description : Bottom openings 15 cm × 15 cm in the standing baffle wall are provided A. 15 cm c/c B. 22.5 cm c/c C. 30 cm c/c D. 50 cm c/c

Last Answer : ANS: B

In detritus tanks, A. Flow velocity is kept 0.09 m/sec B. Detention period is kept 3 to 4 minutes C. Organic and inorganic materials are separated D. All the above

Description : In detritus tanks, A. Flow velocity is kept 0.09 m/sec B. Detention period is kept 3 to 4 minutes C. Organic and inorganic materials are separated D. All the above

Last Answer : ANS: D

For treating the sewage of a large city, you will recommend A. A sedimentation tank and an activated sludge treatment plant B. A plant consisting of Imhoff tanks with low rate trickling filters C. Sedimentation tanks with high rate trickling filters D. None of these

Description : For treating the sewage of a large city, you will recommend A. A sedimentation tank and an activated sludge treatment plant B. A plant consisting of Imhoff tanks with low rate trickling filters C. Sedimentation tanks with high rate trickling filters D. None of these

Last Answer : ANS: A

If the peak discharge of a storm water drain (S.W. Drain) is expected to exceed 150 cumecs, the free board to be provided, is A. 100 cm B. 90 cm C. 80 cm D. 50 cm

Description : If the peak discharge of a storm water drain (S.W. Drain) is expected to exceed 150 cumecs, the free board to be provided, is A. 100 cm B. 90 cm C. 80 cm D. 50 cm

Last Answer : ANS: A

The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is A. 5 m B. 5.5 m C. 6.5 m D. 7 m

Description : The width of a settling tank with 2 hour detention period for treating sewage 378 cu m per hour, is A. 5 m B. 5.5 m C. 6.5 m D. 7 m

Last Answer : ANS: D

The minimum diameter of a sewer is kept A. 10 cm B. 15 cm C. 20 cm D. 25 cm

Description : The minimum diameter of a sewer is kept A. 10 cm B. 15 cm C. 20 cm D. 25 cm

Last Answer : ANS: B

Skimming tanks are A. Used to remove the grease and oil B. Those from which sludge is skimmed out C. Tanks provided with self- cleansing screens D. Improved version of grit chambers

Description : Skimming tanks are A. Used to remove the grease and oil B. Those from which sludge is skimmed out C. Tanks provided with self- cleansing screens D. Improved version of grit chambers

Last Answer : ANS: A

For a continuous flow type of sedimentation tanks A. Width of the tank is normally kept about 6 m B. Length of the tank is normally kept 4 to 5 times the width C. Maximum horizontal flow velocity is limited to 0.3 m/minute D. All the above

Description : For a continuous flow type of sedimentation tanks A. Width of the tank is normally kept about 6 m B. Length of the tank is normally kept 4 to 5 times the width C. Maximum horizontal flow velocity is limited to 0.3 m/minute D. All the above

Last Answer : D

If the over land flow from the critical point to the drain is 8 km and the difference in level is 12.4 m, the inlet time is A. 2 hours B. 3 hours C. 4 hours D. 5 hours

Description : If the over land flow from the critical point to the drain is 8 km and the difference in level is 12.4 m, the inlet time is A. 2 hours B. 3 hours C. 4 hours D. 5 hours

Last Answer : ANS: C

In a cantilever retaining wall without a heel slab (A) Thickness of the stem is kept same throughout (B) Base slab is made 10 cm thicker than the stem (C) Width of the base slab is kept 0.7 time the total height of the wall (D) All the above

Description : In a cantilever retaining wall without a heel slab (A) Thickness of the stem is kept same throughout (B) Base slab is made 10 cm thicker than the stem (C) Width of the base slab is kept 0.7 time the total height of the wall (D) All the above

Last Answer : Answer: Option D

For a ribbed slab (A) Clear spacing between ribs shall not be greater than 4.5 cm (B) Width of the rib shall not be less than 7.5 cm (C) Overall depth of the slab shall not exceed four times the breadth of the rib (D) All the above

Description : For a ribbed slab (A) Clear spacing between ribs shall not be greater than 4.5 cm (B) Width of the rib shall not be less than 7.5 cm (C) Overall depth of the slab shall not exceed four times the breadth of the rib (D) All the above

Last Answer : Answer: Option D

The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is A. 0.68 m B. 0.88 m C. 1.36 m D. 1.76 m

Description : The width of a rectangular sewer is twice its depth while discharging 1.5 m/sec. The width of the sewer is A. 0.68 m B. 0.88 m C. 1.36 m D. 1.76 m

Last Answer : ANS: C

If the length of overland flow from the critical point to the mouth of drain is 13.58 km and difference in level between the critical point and drain mouth is 10 m, the inlet time is A. 2 hours B. 4 hours C. 6 hours D. 8 hours

Description : If the length of overland flow from the critical point to the mouth of drain is 13.58 km and difference in level between the critical point and drain mouth is 10 m, the inlet time is A. 2 hours B. 4 hours C. 6 hours D. 8 hours

Last Answer : ANS: D

15 cumecs, the depth d and width are related by For drains up to A. d = 0.2 B B. d = 0.5 B C. B = 0.2 d D. B = 0.5 d

Description : 15 cumecs, the depth d and width are related by For drains up to A. d = 0.2 B B. d = 0.5 B C. B = 0.2 d D. B = 0.5 d

Last Answer : ANS: B

At the junction of sewers A. Top of smaller sewer is kept lower B. Top of larger sewer is kept lower C. Tops of both the sewers are at the same level D. None of these

Description : At the junction of sewers A. Top of smaller sewer is kept lower B. Top of larger sewer is kept lower C. Tops of both the sewers are at the same level D. None of these

Last Answer : ANS: D

In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above

Description : In a grit chamber of a sewage treatment plant, A. Flow velocity 0.15 m to 0.3 m/sec is kept B. Depth of 0.9 m to 1.20 m is kept C. One minute of detention period is kept D. All the above

Last Answer : ANS: D

The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is A. d² (0.011d + 0.785H)/Q B. d (0.022d + 0.085H)/Q C. d (0.785d + 0.011H)/Q D. d (0.285d + 0.011H)/Q

Description : The detention time of a circular tank of diameter d and water depth H, for receiving the sewage Q per hour, is A. d² (0.011d + 0.785H)/Q B. d (0.022d + 0.085H)/Q C. d (0.785d + 0.011H)/Q D. d (0.285d + 0.011H)/Q

Last Answer : ANS: A

The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours

Description : The settling velocity of the particles larger than 0.06 mm in a settling tank of depth 2.4 is 0.33 m per sec. The detention period recommended for the tank, is A. 30 minutes B. 1 hour C. 1 hour and 30 minutes D. 2 hours

Last Answer : ANS: D

The thickness of base slab of a retaining wall generally provided, is (A) One half of the width of the stem at the bottom (B) One-third of the width of the stem at the bottom (C) One fourth of the width of the steam at the bottom (D) Width of the stem at the bottom

Description : The thickness of base slab of a retaining wall generally provided, is (A) One half of the width of the stem at the bottom (B) One-third of the width of the stem at the bottom (C) One fourth of the width of the steam at the bottom (D) Width of the stem at the bottom

Last Answer : Answer: Option D

Faucet A basically used as inlet pipe and Faucet B is used as outlet pipe. Faucet A and B both are opened simultaneously, all the time. When Faucet A fills the tank and Faucet B empty the tank, it will take thrice the time than when both the pipes fill the tank. When Faucet B is used for filling the tank, its efficiency remains constant. What is the ratio of efficiency of Faucet A and Faucet B respectively? a) 1:2 b) 2:1 c) 1:3 d) 3:1

Description : Faucet A basically used as inlet pipe and Faucet B is used as outlet pipe. Faucet A and B both are opened simultaneously, all the time. When Faucet A fills the tank and Faucet B empty the tank, it will take thrice the ... efficiency of Faucet A and Faucet B respectively? a) 1:2 b) 2:1 c) 1:3 d) 3:1

Last Answer : B Efficiency when both pipes used to fill = A + B And efficiency when Faucet A is used to fill and Faucet B is used to empty the tank = A-B So (A+B)/(A-B)=3/1 A/B+1/(A/B-1)=3/1 A/B+1=3(A/B-1) 3A/B-A/B=4 2A/B=4 A/B=2 Thus, the ratio of efficiency of Faucet A and B =2:1

In centrifugal pump installation, (A) Pump is properly primed before starting (B) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe (C) The motor may burn out if it is started with empty delivery pipe and with open gate valve (D) All the above

Description : In centrifugal pump installation,  (A) Pump is properly primed before starting  (B) The diameter of the pipe at inlet as well as at outlet, is kept smaller than the delivery pipe  (C) The ... out if it is started with empty delivery pipe and with open gate valve  (D) All the above 

Last Answer : (D) All the above 

A tank has two inlet pipes, A and B, which can fill the tank in 12 hours and 18 hours respectively, and an outlet C which can empty the tank in 9 hour

Description : A tank has two inlet pipes, A and B, which can fill the tank in 12 hours and 18 hours respectively, and an outlet C which can empty the tank in 9 hour

Last Answer : A tank has two inlet pipes, A and B, which can fill the tank in 12 hours and 18 hours ... time taken right from the start to fill the tank.

In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient, A. Is only provided B. Is doubled C. Is trebled D. Is not enough

Description : In circular sewers if depth of flow is 0.2 times the full depth, the nominal gradient, A. Is only provided B. Is doubled C. Is trebled D. Is not enough

Last Answer : ANS: B

Pick up the correct statement from the following: A. The circular section of sewers provides maximum hydraulic mean depth B. The circular sewers are provided for separate sewerage system C. The circular sewers work efficiently if the sections run at least half full D. All the above

Description : Pick up the correct statement from the following: A. The circular section of sewers provides maximum hydraulic mean depth B. The circular sewers are provided for separate sewerage system C. The circular sewers work efficiently if the sections run at least half full D. All the above

Last Answer : ANS: D

For laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of A. 100 cm B. 120 cm C. 140 cm D. 160 cm

Description : For laying a sewer line in a trench of 2 m width, an offset line is marked on the ground parallel to the given centre line at a distance of A. 100 cm B. 120 cm C. 140 cm D. 160 cm

Last Answer : ANS: D

If depth of slab is 10 cm, width of web 30 cm, depth of web 50 cm, centre to centre distance of beams 3 m, effective span of beams 6 m, the effective flange width of the beam, is (A) 200 cm (B) 300 cm (C) 150 cm (D) 100 cm

Description : If depth of slab is 10 cm, width of web 30 cm, depth of web 50 cm, centre to centre distance of beams 3 m, effective span of beams 6 m, the effective flange width of the beam, is (A) 200 cm (B) 300 cm (C) 150 cm (D) 100 cm

Last Answer : Answer: Option C

Depth of lean concrete bed placed at the bottom of a wall footing, is kept (A) 10 cm (B) 15 cm (C) Equal to its projection beyond wall base (D) Less than its projection beyond wall base

Description : Depth of lean concrete bed placed at the bottom of a wall footing, is kept (A) 10 cm (B) 15 cm (C) Equal to its projection beyond wall base (D) Less than its projection beyond wall base

Last Answer : Answer: Option C

For providing an Indian type W.C., the R.C.C. slabs in the toilet portion A. Should be sunk by 20 cm B. Should be kept 20 cm above the adjacent portion C. Should be sunk by 50 cm D. Need not be sunk

Description : For providing an Indian type W.C., the R.C.C. slabs in the toilet portion A. Should be sunk by 20 cm B. Should be kept 20 cm above the adjacent portion C. Should be sunk by 50 cm D. Need not be sunk

Last Answer : ANS: C

If the depth of partial flow in a sewer of diameter 2 m, is 50 cm, its wetted perimeter is A. B. /2 C. /3 D. 2 /3

Description : If the depth of partial flow in a sewer of diameter 2 m, is 50 cm, its wetted perimeter is A. B. /2 C. /3 D. 2 /3

Last Answer : ANS: D