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# Multiple choice question for engineering

## Set 1

1. The work done per unit weight of water jet striking runner blades of Pelton turbine is given by expression ______________
a) [Vw1+Vw2] u/g
b) Vw1*u/g
c) [Vw1+Vw2]/g
d) [Vw1+Vw2]u

Answer: a [Reason:] Generally work done is force times velocity and expression for it is PQ [Vw1+Vw2] u/g and work done per unit weight gives [Vw1+Vw2]u/g.

2. In Pelton turbine the energy available at inlet of runner that is at outlet of nozzle is known as
a) Shaft power
b) Runner power
c) Output power
d) Water power

Answer: b [Reason:] In Pelton turbine the energy available at inlet of runner that is at outlet of nozzle is known as runner power, the energy available in penstock is water energy.

3. In Pelton turbines the expression for power delivered at inlet to runner is given by __________
a) W*[Vw1+Vw2]u/g
b) W*[Vw1-Vw2]u/g
c) W*[Vw1+Vw2]u/g, W*[Vw1-Vw2]u/g
d) [Vw1+Vw2]u/g

Answer: c [Reason:] Generally work done is force times velocity and expression for it is PQ [Vw1+Vw2] u/g and work done per unit weight gives [Vw1+Vw2]u/g.

4. In Pelton turbine runner power is more when compared with power available at exit of nozzle.
a) True
b) False

Answer: b [Reason:] Runner power is less when compared with power available at exit of nozzle due to frictional losses.

5. Kinetic energy of jet at inlet of turbine is given as __________________
a) 0.5(paV1)*V1
b) 0.5(paV1)*V1*V1
c) 0.5(aV1)*V1*V1
d) 0.5(pV1)*V1*V1
p= density of liquid, a= area of jet, V1= inlet jet velocity

Answer: b [Reason:] Expression for kinetic energy is product of half times mass and square of velocity, mass can be written as density time volume.

6. The force exerted by a jet of water in the direction of jet of jet on a stationary curved plates Fx is ____________
a) pav*v
b) pav
c) pav*v(1+cos k)
d) pav*v(1+sin k)
p=density, v= velocity of jet, k= blade angle

Answer: c [Reason:] Generally force is rate of change of momentum, in curved blade of angle k change of momentum will be pav*v (1+cos k).

7. The force exerted by a jet of water in the direction of jet of jet on moving curved plates is ___________
a) pa(v-u)*(v-u)
b) pa(v-u)
c) pav*(v-u)(1+cos k)
d) pa(v-u)*(v-u)(1+sin k)

Answer: c [Reason:] Generally force is rate of change of momentum, in curved blade of angle k change of momentum will bepav*(v-u)(1+cos k) here relative velocity is considered than absolute.

8. Calculate work done by jet per second on the runner where, discharge=0.7cubic meters/s, inlet and outlet whirl velocities be 23.77 and 2.94?
a) 200Kw
b) 150Kw
c) 187Kw
d) 250Kw

Answer: c [Reason:] As we know the expression for work done per second is W*[Vw1+Vw2] u/g on substituting the above given values we get it as 187Kw.

9. The power supplied at inlet of turbine in S.I units is known as_____________
a) Shaft power
d) Runner power
c) Water power
d) Total power

Answer: c [Reason:] The power supplied at inlet of turbine in S.I units is known as water energy, which contain both kinetic energy and pressure energy.

10.The expression for water power in Pelton wheel is ________________
a) (P*g*Q*H) Kw
b) (g*Q*H*a) Kw
c) (g*Q) Kw
d) (g*H) Kw

Answer: a [Reason:] Expression for water power of Pelton turbine is potential energy of water which is converted into kinetic energy can be written as (P*g*Q*H) Kw.

## Set 2

1. Internal breakage in a pump mainly takes place when ________
a) Discharge pressure is increased
b) Temperature is increased
d) Corrosion takes place

Answer: a [Reason:] Internal breakage in a pump mainly takes place when the discharge pressure in the pump is increased in between that of the piston rings and the cylinder liner or the leading internal valves.

2. During internal breakage, output power ________
a) Increases
b) Decreases
c) Remains same
d) Independent

Answer: b [Reason:] During internal breakage, output power decreases. This is an important measure to determine the volumetric efficiency of the pump.

3. The output that we get after an internal breakage can be classed as _________
a) An increase
b) A decrease
c) Constant
d) An independent variable

Answer: c [Reason:] The output that we get after an internal breakage can be classed as an independent variable. During internal breakage, output power decreases. This is an important measure to determine the volumetric efficiency of the pump.

4. When the hydraulic fluid forms on only one side of the piston, it is called _______
a) Single acting pump
b) Double acting pump
c) Froth pump
d) Draft tube

Answer: a [Reason:] When the hydraulic fluid forms on only one side of the piston, it is called a single acting pump.

5. The speed of the reciprocating pump is generally measured in ______
a) Stokes.min
b) Stokes/min
c) rps
d) rp/s

Answer: b [Reason:] The speed of the reciprocating pump is generally measured in stokes/min. This is the number of times the piston moves backward and forth in one minute. It can also be measured in rpm.

6. A pump with two steams and two water cylinders is called ________
a) Single acting pump
b) Double acting pump
c) Froth pump
d) Duplex pump

Answer: d [Reason:] A pump with two steams and two water cylinders is called duplex pumps. It consists of a basic hydraulic system layout.

7. Reciprocating pumps can deliver fluid at high pressure.
a) True
b) False

Answer: a [Reason:] Reciprocating pumps can deliver fluid at high pressure. It can do it with its high delivery head. This is one of the major advantage of reciprocating pumps.

8. When an external force is not available in a pump, we use a ________
a) Hydraulic cylinder
b) Slip gauge
c) Tail race
d) Heater

Answer: a [Reason:] When an external force is not available in a pump, we use a hydraulic cylinder attached at the port end.

9. Piston pumps are self priming.
a) True
b) False

Answer: a [Reason:] The statement is true. Piston pumps are self priming. They do not need cylinders to be filled before the starting of the operation. This is one of the major advantage of the piston pumps.

10. Reciprocating pumps give a ________ flow
a) Uniform
b) Non- uniform
c) Pulsating
d) Sinusoidal

Answer: c [Reason:] Reciprocating pumps give a pulsating flow. Reciprocating pumps can deliver fluid at high pressure. It can do it with its high delivery head. This is one of the major advantage of reciprocating pumps.

11. Suction stroke becomes difficult to pump ______
a) High temperature fluids
b) Viscous fluids
c) Fluids with abrasives
d) High velocity fluids

Answer: b [Reason:] For a good condition of the pump, the slip should be below 1 percent. Suction stroke becomes difficult to pump when the fluid is of high viscosity.

12. Piston pumps are very _______
a) Expensive
b) Cheap
c) Reasonable
d) Intricate

Answer: a [Reason:] The piston pumps are very expensive because of their accurate sizes of the cylinders and their pistons. Also, they require a conversion of their gearing that involves extra equipment cost.

13. What is the full form of DAC?
a) Digital Acting pumps
b) Double acting pumps
c) Data acting pumps
d) Draft tube pumps

Answer: b [Reason:] DAC stands for Double acting pumps. Suction stroke becomes difficult to pump when the fluid is of high viscosity in a double acting pump.

14. Which among the following is not a multi-cylinder pump?
a) Double acting simplex
b) Single acting duplex
c) Double acting duplex
d) Single acting triplex

Answer: a [Reason:] Double acting simplex is not a multi-cylinder pump. It is a single cylinder pump. The more the double acting cylinders in a pump, the smoother the operation is providing a better output.

15. As the motor rotates the flywheel, the eccentrically mounted connecting rod rotates with it.
a) True
b) False

Answer: a [Reason:] As the motor rotates the flywheel, the eccentrically mounted connecting rod rotates with it. The other end of the connecting rod is coupled to the slide assembly or the cross head gear.

## Set 3

1. What are the impurities added in the steel?
a) Silicon
b) Manganese
c) Sulphur
d) Silicon, Manganese, Sulphur

Answer: d [Reason:] Impurities percentage is very minimal, and it is added according to the requirements • Silicon • Sulphur • Carbon • Phosphorous • Manganese, etc.

2. What are the main challenges does steel industry is facing now?
a) High raw material cost
b) Overcapacity
c) Price volatility
d) High Raw Material Cost, Overcapacity, Price Volatility

Answer: d [Reason:] It is a rate at which the price of a security increases or decreases for a given set of returns. Volatility is measured by calculating the standard deviation of the annualized returns over a given period of time. It shows the range to which the price of a security may increase or decrease.

3. Because of its low tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons.
a) True
b) False

Answer: b [Reason:] Because of its high tensile strength and low cost, it is a major component used in buildings, infrastructure, tools, ships, automobiles, machines, appliances, and weapons.

4. Iron is commonly found in the Earth’s crust in the form of an ore, usually an iron oxide.
a) True
b) False

Answer: a [Reason:] Iron is extracted from iron ore by removing the oxygen through its combination with a preferred chemical partner such as carbon which is then lost to the atmosphere as carbon dioxide. This process, known as smelting, was first applied to metals with lower melting points, such as tin, which melts at about 250 °C (482 °F), and copper, which melts at about 1,100 °C (2,010 °F), and the combination, bronze, which has a melting point lower than 1,083 °C (1,981 °F).

5. PCI stands for – Pulverized Coal Injection Method.
a) True
b) False

Answer: a [Reason:] Pulverized Coal Injection (PCI) is a process that involves blowing large volumes of fine coal granules into the BF. This provides a supplemental carbon source to speed up the production of metallic iron, reducing the need for coke production. As a result energy use and emissions can be reduced.

6. Pig iron is a pure iron.
a) False
b) True

Answer: a [Reason:] Pig iron is an intermediate product of the iron industry. Pig iron has a very high carbon content, typically 3.8–4.7%, along with silica and other constituents of dross, which makes it very brittle, and not useful directly as a material except for limited applications.

7. Iron products make 10-15% of the total world metal production.
a) True
b) False

Answer: b [Reason:] Iron products make 90-95% of the total world metal production. The World’s largest producer of iron is China with over 60% share in world production, followed by Japan with around 7%, and Russia and India with about 4%.

8. Mild iron deficiency can be prevented or corrected by eating iron-rich foods and by cooking in an iron skillet.
a) True
b) False

Answer: a [Reason:] Because iron is a requirement for most plants and animals, a wide range of foods provide iron. Good sources of dietary iron have heme-iron, as this is most easily absorbed and is not inhibited by medication or other dietary components. Three examples are red meat, poultry, and insects. Non-heme sources do contain iron, though it has reduced bioavailability. Examples are lentils, beans, leafy vegetables, pistachios, tofu, fortified bread, and fortified breakfast cereals.

9. Blast furnace is a technique used to raise the temperature up to 2200 degree C in the furnace.
a) True
b) False

Answer: a [Reason:] In a blast furnace fuel (coke), ores, and flux (limestone) are continuously supplied through the top of the furnace, while a hot blast of air (sometimes with oxygen enrichment) is blown into the lower section of the furnace through a series of pipes called tuyeres, so that the chemical reactions take place throughout the furnace as the material falls downward. The end products are usually molten metal and slag phases tapped from the bottom, and flue gases exiting from the top of the furnace.

10. The main types of stainless steel are Ferritic, Austenitic, Martensitic.
a) True
b) False

Answer: a [Reason:] ‘Stainless’ is a term coined early in the development of these steels for cutlery applications. It was adopted as a generic name for these steels and now covers a wide range of steel types and grades for corrosion or oxidation resistant applications. Stainless steels are iron alloys with a minimum of 10.5% chromium. Other alloying elements are added to enhance their structure and properties such as formability, strength and cryogenic toughness.

## Set 4

1. The ____________ is made of bricks and cement mortar and it’s inside wall are plastered with a mixture of cement and sand.
a) Foundation
b) Digester
C) Gas holder
d) Inlet and outlet pipe

Answer: b [Reason:] Digester (Fermentation chamber) of KVIC is a cylindrical shaped well like structure, constructed using the foundation as its base. The digester is made of bricks and cement mortar and it inside walls are plastered with a mixture of cement and sand.

2. From what material is biogas holder drum made?
a) Mild steel
b) Cast iron
c) Aluminum alloys
d) Rot iron

Answer: a [Reason:] The biogas holder drum of KVIC model is normally made of mild steel sheets. The biogas holder rests on a ledge constructed inside the walls of the digester well. If the KVIC model is made with water jacket on top of the digester wall, no ledge is made and the drum of the biogas holder is placed inside the water jacket.

3. What is the weight of biogas holder?
a) 8-10 kg/m2
b) 10-15 kg/m2
c) 8-18 kg/m2
d) 25-30 kg/m2

Answer: a [Reason:] The weight of the biogas holder is 8-10 kg/m2. The biogas holder of KVIC (Khadi village industries biogas plant) is also fabricated out of fiber glass reinforced plastic (FRP), high density polyethylene (HDP) or Ferroconcrete (FRC).

4. What type of movement does a biogas holder of KVIC has?
a) Linear Movement
b) Transverse movement
c) Rotary movement
d) Circular movement

Answer: c [Reason:] The biogas holder of a KVIC moves up and down on a guide pipe situated in the centre of the digester. The biogas holder has a rotary movement that helps in breaking the scum-mat formed on the top surface of the slurry. The weight of the biogas holder is 8-10 kg/m2. So that it can store biogas at a constant pressure of 8-10 cm of water column.

5. How is the inlet pipe of KVIC made?
a) Cement mortar
b) Asbestos cement concrete
c) White cement
d) PVC

Answer: b [Reason:] The inlet pipe is made out of cement concrete (CC) or Asbestos cement concrete (ACC) or pipe. The one end of the inlet pipe is concrete to the mixing tank and the other end goes inside the digester on the inlet side of the partition wall and rests on a support made of bricks of about 1 feet height.

6. How is the outlet pipe of KVIC made?
a) Cement mortar
b) Asbestos cement concrete
c) White cement
d) PVC

Answer: b [Reason:] The outlet pipe is made out of cement concrete (CC) or asbestos cement concrete (ACC) or pipe. The one end of the outlet pipe is connected to the outlet tank and the other end goes inside the digester, on the outlet side of the partition wall and rests on a support made of about bricks of about 1 feet height.

7. How is the Biogas outlet pipe of KVIC made?
a) Cement
b) PVC
c) Asbestos
d) GI pipe

Answer: d [Reason:] The biogas outlet pipe is fixed on the top middle portion of the biogas holder, which is made of a small of GI pipe fitted with socket and a gat valve. The biogas generated in the plant and stored in the biogas holder is taken through the gas outlet pipe via pipeline to the place of utilization.

8. What is the life time of Floating drum plant?
a) Short
b) Large
c) Life time
d) Average

Answer: a [Reason:] Even though the floating drum plant is built with all reinforced constituents and hard materials the life of floating drum plant is short which is upto 15 years; And in tropical coastal regions its just about 5 years.

9. Which plant has no movable parts?
a) KVIC
b) JANATA model
c) Pragati design plant
d) Ferro – cement plant

Answer: b [Reason:] The janata model consists of a digester and fixed biogas holder as gas storage chamber covered by a dome shaped enclosed roof structure. The entire plant is made of bricks and cement masonry and constructed underground. Unlike the KVIC, the janata model has no movable part.

10. Which part of the janata bio gas plant comprises of the fermentation chamber and the gas storage chamber?
a) Foundation
b) Digester
c) Inlet chamber
d) Outlet chamber

Answer: b [Reason:] The digester is a cylindrical tank resting on the foundation. The top surface of the foundation serves as the bottom of the digester. The digester of janata biogas plant comprises of the fermentation chamber and the gas storage chamber.

11. The Gas storage chamber of the digester of janata model is designed to store what percentage og daily gas?
a) 5%
b) 19%
c) 33%
d) 58%

Answer: c [Reason:] The gas storage chamber is also cylindrical in shape and is the integral part of the digester and located just above the fermentation chamber. The GSC is designed to store 33% of the daily gas production from the plant.

12. Which plant has fixed hemi-spherical roof?
a) Fixed dome plant
b) Floating drum plant
c) Chinese plant
d) Flexible bag biogas plant

Answer: a [Reason:] Fixed dome plant has a fixed hemi-spherical roof which forms the cover of the digester and constructed with brick and cement concrete mixture, after which it is plastered with cement mortar. The dome is only an enclosed roof designed in such a way to avoid steel reinforcement.

13. The upper portion of the ______________ is in the shape of bell mouth and constructed using bricks and cements mortar in fixed dome plant.
a) gas storage chamber
b) inlet chamber
c) outlet chamber
d) digester

Answer: b [Reason:] The upper portion of the inlet chamber is in the shape of bell mouth and constructed using bricks and cements mortar in fixed dome plant. It s outer wall is kept inclined to the cylindrical wall of the digester so that the feed material can flow easily into the digester by gravity.

14. The outer chamber upper is called as ______
a) outlet displacement chamber
b) outlet discharge chamber
c) outlet density chamber
d) outlet dwell chamber

Answer: a [Reason:] Outer chamber is a rectangular shaped located just on the opposite side of the inlet chamber. The bottom opening of the outlet chamber is connected to the gate and the upper portion is much wider and is known as Outlet displacement chamber (ODC).

## Set 5

1. How are systems intended for the digestions are filled and emptied?
a) Manually
b) By evaporation
c) By pumps and pipes
d) By channels and pits

Answer: c [Reason:] Systems intended for the digestion of liquid or suspended solid waste (cow manure is a typical example of this variety) are mostly filled or emptied using pumps and pipe work. A simple version is simply to gravity feed the tank allow the digested slurry to overflow the tank.

2. Cow manure is rich in __________
a) Hydrogen
b) Phosphorus
c) Nitrogen
d) Potassium

Answer: c [Reason:] Cow dung is the undigested residue of plant matter which has passed through the animal’s gut. The resultant fecal matter is rich in minerals. Color ranges from greenish to blackish, often darkening soon after exposure to air. And it is very rich in nitrogen.

3. How many weeks does complete digestion of cow manure takes about?
a) 1
b) 2
c) 4
d) 8

Answer: d [Reason:] The complete anaerobic digestion of cow manure takes about 8 weeks at normally warm temperatures. One third of the total biogas will be produced in the first week, another quarter in the second week and the remainder of the biogas production will be spread over the remaining 6 weeks.

4. How many weeks does a batch digester need to produce biogas?
a) 1 week
b) 2 – 4 week
c) 12 week
d) 4 – 8 week

Answer: b [Reason:] Depending on the waste material and operating temperature, a batch digester will start producing biogas after 2 – 4 weeks, slowly increase in production then drop off after three or 4 months. Batch digesters are therefore best operated in groups.

5. Which of the following matter has a much higher carbon – nitrogen ratio?
a) Vegetable matter
b) Cow dung
c) Plant waste
d) Organic waste from industry

Answer: a [Reason:] Most vegetable matte has a much higher carbon – nitrogen ratio than dung has, so some nitrogen producers (preferably organic) must generally be added to vegetable matter, especially when batch digestion is used.

6. Which of the following waste produces more gases comparatively?
a) Vegetable matter
b) Cow dung
c) Plant waste
d) Organic waste from industry

Answer: a [Reason:] Vegetable matter produces about 8 times more gas, so the quantity required is much smaller in batch production for the same gas production from any other wastes. A mixture of dung and vegetable matter is hence ideal in most ways, with a majority of vegetable matter to provide the biogas and the valuable methane contained in it.

7. How much thick layer of insulation is done inside of digester?
a) 10 cm
b) 15 – 25 mm
c) 8 mm
d) 50 – 100 cm

Answer: d [Reason:] In hot regions it is relatively easy to simply shade the digester to keep it in the ideal range of temperature, but cold climates present more of a challenge. The first action is, naturally, to insulate the digester with straw or wood shavings. A layer about 50 – 100 cm thick, coated with a waterproof covering is a good start.

8. What happens if the organic matter is not stirred while in process of digestion?
a) It will evaporate
b) It solidifies
c) It will form hard scum on layer
d) It gets struck to digester walls

Answer: c [Reason:] Some method of stirring the slurry in a digester is always advantageous, if not essential. If not stirred, the slurry will tend to settle out and form a hard scum on the surface, which will prevent release of biogas.

9. How is biogas from an anaerobic digester collected?
a) In a compressor
b) In the pipelines
c) In inverted drum
d) In a storage tank

Answer: c [Reason:] The biogas in an anaerobic digester is collected in an inverted drum. The walls of the drum extended down into the slurry to provide a seal. The drum is free to move to accommodate more or less gas needed.

10. Which type of valve is used to prevent air being drawn into the digester?
a) Non return valve
b) Poppet vale
c) Return valve
d) Check valve

Answer: a [Reason:] A non return valve is a valuable investment to prevent air being drawn into digester, which would destroy the activity of bacteria and provided a potentially explosive mixture inside the drum. Larger plants may need counterweights of some sort to ensure that the explosive mixture inside the drum.

11. Which types of plants are filled and then emptied completely after fixed retention time?
a) Batch plants
b) Continuous plants
c) Floating gas holder plants
d) Flexible bag biogas plant

Answer: a [Reason:] Batch plants are filled and then emptied completely after a fixed retention time. Each design and each fermentation material is suitable for batch filling, but batch plants require high labor input.

12. What is the major disadvantage of batch plants?
a) Their output is not steady
b) Comes to frequent breakdown
c) They are not efficient
d) They are very costly

Answer: a [Reason:] Batch biogas plants are loaded with substrate completely and after some determined digestion time are fully unloaded. For this loading method any design of biogas plant and any design of biogas plant any substrate can be used, but such plants are distinguished by unstable biogas production. The major disadvantage of batch plant is the output is not steady.

13. Which among the following best suitable treatment of waste products?
a) Aerobic fermentation
b) Anaerobic fermentation
c) Autolysis
d) Thermal reaction

Answer: b [Reason:] Anaerobic process is especially considered as a suitable treatment option due to low-energy requirements and little quantities of sludge production. Therefore, anaerobic process has become increasingly demanding in the treatment of complex industrial wastes.

14. What does PSD stand for?
a) Post source decay
b) Particle size distribution
c) Polystyrene deuterated
d) Post synaptic density