Multiple choice question for engineering
Set 1
1. Coning plume occurs under which conditions?
a) Super adiabatic
b) Sub adiabatic
c) Neutral
d) Inversion
Answer
Answer: b [Reason:] Coning occurs under sub adiabatic conditions. The plume is of conical shaped.
2. In which of the following plumes, stable condition prevails?
a) Lofting
b) Fanning
c) Neutral
d) Fumigating
Answer
Answer: b [Reason:] The stability prevails in Fanning plume. It occurs during inversion conditions.
3. The upward vertical rise prevails in which of the following plume?
a) Trapping
b) Fanning
c) Looping
d) Neutral
Answer
Answer: d [Reason:] In Neutral plume, the Environmental lapse rate is equal to the Adiabatic lapse rate.
4. Which of the following plume is worst for the dispersion of pollutants?
a) Trapping
b) Fanning
c) Neutral
d) Fumigating
Answer
Answer: d [Reason:] In Fumigating plume, the pollutants come down near the ground due to turbulence instead of escaping above the stack. This makes it the most dangerous plume.
5. In which of the following plumes, unstable condition prevails?
a) Trapping
b) Fanning
c) Looping
d) Neutral
Answer
Answer: c [Reason:] Rapid dispersion of pollutants takes place under Looping plume. It occurs under super adiabatic conditions.
6. Which of the following are contradictory plume?
a) Lofting and fumigating
b) Looping and coning
c) Neutral and lofting
d) Fumigating and trapping
Answer
Answer: a [Reason:] In Lofting plume, the super adiabatic lapse rate occurs above the stack, whereas, in Fumigating plume, it occurs below the stack.
7. The maximum efficiency of electrostatic precipitator is
a) 95%
b) 80%
c) 99%
d) 100%
Answer
Answer: c [Reason:] The efficiency of Electrostatic precipitator lies between 95% to 99%. They are used in thermal power plants.
8. The minimum particle size removes by gravitational chamber is
a) >50μm
b) >10μm
c) >25μm
d) >0.5μm
Answer
Answer: a [Reason:] The minimum particle size removes by Gravitational settling chamber is >50μm and its efficiency is less than 50%.
Set 2
1. Which of the following is the correct classification of pumps?
a) Physical principle of operation
b) Mechanical principle of operation
c) Chemical principle of operation
d) Biological principle of operation
Answer
Answer: b [Reason:] The pumps are classified on the basis of the mechanical operation of the principle, type of power and type of service.
2. Displacement pump is classified on the basis of
a) Mechanical operation of principle
b) Type of power
c) Type of service
d) Efficiency
Answer
Answer: a [Reason:] Mechanical principle of operation is classified into displacement, centrifugal, air lift and miscellaneous pumps.
3. Which of the following pump is classified based on the type of service?
a) Displacement pump
b) Centrifugal pump
c) Deep well pump
d) Electric driven pump
Answer
Answer: c [Reason:] Pumps are of four types on the basis of type of service- low lift, high lift, deep well and booster pump.
4. Which of the following pump is based on the type of power?
a) Low lift pump
b) High lift pump
c) Air lift pump
d) Steam engine pump
Answer
Answer: d [Reason:] There are 3 types of pumps on the basis of type of power. They are – steam engine, diesel engine and electrically driven pump.
5. A booster pump is based on
a) Mechanical operation of principle
b) Type of power
c) Type of service
d) Efficiency
Answer
Answer: c [Reason:] Booster pump is classified on the basis of type of service. They are used for increasing gas pressure, transferring high pressure gas, scavenging and charging gas cylinders.
6. Consider the following statements.
1. Capacity of the pump
2.Number of pump units
3.Discharge condition
The selection of a particular type of pump depends on which of the following?
a) 1, 2, 3
b) 1 only
c) 2, 3
d) 1, 3
Answer
Answer: a [Reason:] The selection of a particular type of pump depends on the capacity of pump, number of pump units, suction and discharge condition, type of drive, initial and final cost, lift, flexibility of operations and floor space requirements.
7. The centrifugal pump has a ______ flow.
a) Variable
b) Uniform
c) Continuous
d) Constant
Answer
Answer: c [Reason:] The centrifugal pump has a continuous flow. It does not give a constant discharge under variable head.
8. The speed at which the centrifugal pump runs (in r.p.m) is
a) 200
b) 300
c) 500
d) 1200
Answer
Answer: c [Reason:] The speed at which the centrifugal pump runs lies in the range of 500 to 100 rates per minute (r.p.m). The direct connection of pump with driving machines is possible.
9. The maximum efficiency of a centrifugal pump is
a) 50%
b) 60%
c) 85%
d) 100%
Answer
Answer: c [Reason:] The efficiency of the centrifugal pump lies between 40% and 85%. It depends on the head and discharge of the pump.
10. Based on the type of casing, the centrifugal pump is divided into _____ types.
a) 2
b) 3
c) 4
d) 5
Answer
Answer: a [Reason:] Based on the type of casing, the centrifugal pump is divided into the volute pump and turbine pump.
Set 3
1. Which of the following is known as Shut off valve?
a) Air relief valve
b) Sluice valve
c) Pressure relief valve
d) Altitude valve
Answer
Answer: b [Reason:] Sluice valve is called as shut off valve as the water in pipes can be shut off from them. They offer no resistance to the flow of water when the valve is wide open.
2. The spacing between the Sluice valves is
a) 10m
b) 30m
c) 80m
d) 180m
Answer
Answer: d [Reason:] The spacing between the Sluice valves lies between 150-300m. They can be placed at street corners or where the two pipelines intersect.
3. Which of the following is used to stop the water supplies when required?
a) Air relief valve
b) Sluice valve
c) Pressure relief valve
d) Altitude valve
Answer
Answer: b [Reason:] Sluice valves are used to stop the water supplies when required.They are also helpful in dividing the water mains into suitable sections.
4. The Gate valves are made of _______ with brass mountings.
a) Cement concrete
b) Reinforced concrete
c) Cast iron
d) Galvanized iron
Answer
Answer: c [Reason:] The Gate valves are made of cast iron with brass mountings. They are of two types, namely solid wedge type and double disk type.
5. _______ valves are used to discharge air from the water pipelines.
a) Air relief valve
b) Sluice valve
c) Pressure relief valve
d) Altitude valve
Answer
Answer: a [Reason:] The water flowing through the water pipelines contains some air, which may interfere with the flow. So, it is removed with the help of Air relief valves.
6. _________ valve allows water to flow in one direction only.
a) Air relief valve
b) Sluice valve
c) Reflux valve
d) Altitude valve
Answer
Answer: c [Reason:] Reflux valves are an automatic device which allows water to flow in one direction only and avoids the back flow of water or prevents the damage of the pump.
7. Which of the following is known as washout valve?
a) Scour valve
b) Sluice valve
c) Reflux valve
d) Altitude valve
Answer
Answer: a [Reason:] Scour valve is known as washout valve. They are either located at the dead ends or at the lowest point in the mains.
8. Which of the following valve is known as a safety valve?
a) Scour valve
b) Pressure relief valve
c) Reflux valve
d) Altitude valve
Answer
Answer: b [Reason:] Pressure relief valve is known as automatic cut off or safety valves. They are located at points where pressure is likely to be maximized.
9. Which of the following is also known as check valve?
a) Scour valve
b) Pressure relief valve
c) Altitude valve
d) Reflux valve
Answer
Answer: d [Reason:] Reflux valve is known as non-return valve or check valve. They are placed in water pipes which obtain water directly from the pumps.
10. The valve which is preferred in elevated tanks and stand pipes is
a) Altitude valve
b) Pressure relief valve
c) Reflux valve
d) Air relief valve
Answer
Answer: a [Reason:] Altitude valve is preferred in elevated tanks and stand pipes.They are open when the pressure on the pump side is less than the tank side of the valve.
11. ______ valves are used to remove sand and silt from the pipelines.
a) Air relief valve
b) Sluice valve
c) Scour valve
d) Altitude valve
Answer
Answer: c [Reason:] Scour valves are provided to blow off the sand and silt deposited in the pipeline. This operation is done manually.
Set 4
1. In which type of filter, water flows in upward direction?
a) Slow sand filter
b) Rapid sand filter
c) Pressure filter
d) Up flow filter
Answer
Answer: d [Reason:] Up flow filter is a rectangular or round shape filter in which water flows in upward direction.
2. State whether the following statement is true or false.
The up flow filter is used in domestic water supply.
a) True
b) False
Answer
Answer: b [Reason:] The up-flow filter is not used in domestic water supply because sudden variation in pressure breaks the sand bridge and cause the bed to expand.
3. In which type of filter, the filtration is done in two opposite directions at the same time?
a) Dual media filter
b) Mixed media filter
c) Bi-flow filter
d) Rapid sand filter
Answer
Answer: c [Reason:] In Bi-flow filter, the filtration is done in the opposite direction at the same time. It is divided into single media and dual media bi-flow filter.
4. Which material is provided for the down-flow bed in dual media bi-flow filter?
a) Coal sand
b) Garnet sand
c) Rice husk
d) Graphite
Answer
Answer: a [Reason:] In dual media bi-flow filter, coal sand is provided, If the sand is finer than that provided in rapid sand filter, excessive amount of sand will rise into coal bed and sand will become coarser.
5. The rate of filtration of a Micro-Strainer is __________ litres / hour.
a) 10,000-20,000
b) 20,000-30,000
c) 40,000-60,000
d) 50,000-80,000
Answer
Answer: d [Reason:] The rate of filtration of a Micro-Strainer is 50,000-80,000 litres per hour. It cannot remove color and other finely divided particles.
6. Which material is provided for the up flow bed in dual media bi-flow filter?
a) Anthracite
b) Sand
c) Rice husk
d) Graphite
Answer
Answer: b [Reason:] Sand is provided for the up-flow bed in dual media bi-flow filter. The quality of effluent obtained from up-flow bed in dual media bi-flow filter is inferior than that of the mixed media filter.
7. Which device is used for screening stored water which do not contain microscopic sized particles?
a) Tube settler
b) Clarifier
c) Flocculator
d) Micro-Strainers
Answer
Answer: d [Reason:] Micro-Strainers are stainless steel wire cloth that is used for screening stored water that do not contain algae, plankton and micro sized particles.
8. What is the diameter of drum of a Micro-Strainer?
a) 1m
b) 2m
c) 3m
d) 4m
Answer
Answer: c [Reason:] The diameter of a drum of Micro-Strainer is 3m and it is 3m wide and single unit of it can deal with about 50,000-80,000 litres/ hour.
9. What is the thickness of a layer of a diatomite filter?
a) 1mm
b) 2mm
c) 3mm
d) 4mm
Answer
Answer: c [Reason:] Diatomite filter consists of a layer of diatomaceous earth, having a thickness of 3mm supported on a filter element called the septum.
10. The diatomite is applied on the septum at the rate of ______
a) 100gm/m2
b) 200gm/m2
c) 300gm/m2
d) 400gm/m2
Answer
Answer: c [Reason:] The diatomite is applied on the septum at the rate of 300gm/m2 to form a precoat of filter media.
11. Consider the following statements regarding diatomite filters.
1. They are not used for water having high turbidity.
2. They are not suitable for municipal water supplies.
3. They are not used for temporary and shifting camps.
Which of the above statement is/are false?
a) 1, 2,3
b) 1 only
c) 2 only
d) 3 only
Answer
Answer: d [Reason:] The diatomite filter is useful for temporary and shifting camps because they require less space, are lighter in weight and are more mobile.
Set 5
1. Into how many types, the water carriage system is divided?
a) 2
b) 3
c) 4
d) 5
Answer
Answer: b [Reason:] The water carriage system is divided into a separate system, combined system and partially separate system.
2. The number of separate systems in a sewer area
a) 2
b) 3
c) 4
d) 6
Answer
Answer: a [Reason:] There are two separate systems of sewer, one for the conveyance of foul smell and other in the rain water.
3. State whether the following statement is true or false.
The water carriage system is more suitable in rural conditions.
a) True
b) False
Answer
Answer: b [Reason:] The water carriage system is more suitable in urban conditions, whereas the conservancy system is more suitable in rural conditions.
4. Which of the following is an advantage of a separate water carriage system?
a) Get choked easily
b) Difficult to clean the sewer
c) Two sets of sewer are used
d) The more uniform character of sewage
Answer
Answer: d [Reason:] The sewage in the separate water carriage system will be of more uniform character and it will lend itself more easily to purification.
5. Which of the following is a disadvantage of a separate water carriage system?
a) Low installation charge
b) No loads on treatment units
c) Lesser air contact with small sized sewer
d) Provision of the automatic flushing tank is not required
Answer
Answer: c [Reason:] In a separate water carriage system, because of lesser air contact with small sized sewer, foul smell is formed due to the formation of sewage gas.
6. _______ provides only one sewer to carry both foul sewage and rainwater.
a) Separate water carriage system
b) Combined water carriage system
c) Partially combined water carriage system
d) Conservancy system
Answer
Answer: b [Reason:] In combined water carriage system, the sewage and the rain water are carried to the treatment units through only one sewer, before its final disposal.
7. Which of the following is correct regarding combined water carriage system?
a) The sewers are of small size
b) The strength of sewer is reduced by dilution
c) Low cost of construction
d) More chances of choking are there
Answer
Answer: b [Reason:] In the combined water carriage system, a) The sewers are of large size, the strength of sewer is reduced by dilution, there is the high cost of construction and rare chances of choking.
8. Which of the following is an advantage of the combined water carriage system?
a) There is more air in large sewer
b) There is the inclusion of storm water
c) There is difficulties in ventilation of large sewer
d) Overflowing of sewer
Answer
Answer: a [Reason:] In combined water carriage system, due to more air in large sewer, the sewer gas formed gets diluted and the chances of foul smell reduces.
9. Which of the following is incorrect regarding partially combined water carriage system?
a) The sewers are of reasonable size
b) There is choking of sewer
c) The storm water increases load on treatment units
d) The storm water increases the cost of pumping
Answer
Answer: b [Reason:] The storm water permitted in the sewer eliminates its chances of choking. The sewers are completely cleaned during rainy season.
10. The choice of combined water carriage system does not depend on
a) Space consideration
b) Even rainfall pattern
c) Steep topography
d) Pumping requirements
Answer
Answer: c [Reason:] The choice of a combined water carriage system depends on space consideration, even rainfall pattern,conversion of existing storm water drains and pumping requirements.