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Multiple choice question for engineering

Set 1

1. Gravitational separator works on the principle of__________
a) Size of particulate
b) Shape of particulate
c) Weight of particulate
d) Color of the particulate

View Answer

Answer: c [Reason:] Gravitational separation is an industrial method of separating two components, either a suspension, or dry granular mixture where separating the components with gravity is sufficiently practical, i.e. the components of the mixture have different specific weights.

2. What is the use of baffles in the gravitational separators?
a) To separate types of dust
b) To settle the dust by letting them to strike
c) To control the flow of dust particles
d) To blow the dust

View Answer

Answer: b [Reason:] Baffles are placed in the direction of flow of flue gases. The dust particle strike down and settle. Heavier dust particles settle at the bottom by striking on to the baffles and lighter dust particles are exhaust into atmosphere.

3. What is the most effective advantage of gravitational separators?
a) They consume no power
b) They just need small amount of space for operation
c) They are cost effective
d) Time taken for operation is very less

View Answer

Answer: c [Reason:] The most notable advantage of the gravitational separators is their cost effectiveness. Gravity separation is an attractive unit operation as it generally has low capital and operating costs, uses few if any chemicals that might cause environmental concerns.

4. Which principle does cyclone separator use?
a) Gravitational force
b) Vortex velocity
c) Inertia
d) Temperatures of air

View Answer

Answer: c [Reason:] Cyclone separators or simply cyclones work on the principle of inertia to move particulate matter from flue gases. In these high velocity dusts carrying gas is made to pass through conical separator in tangential direction. This results in centrifugal action, throwing away the heavier dust particles to the sides of conical chamber.

5. Cyclone separators are also known as:
a) Twist cleaners
b) Squall
c) Pre-cleaners
d) Zephyr cleaners

View Answer

Answer: c [Reason:] Cyclone separators are a part of a group of air pollution control devices known as pre-cleaners as they generally used to roughly remove large pieces of particulate matter. This prevents finer filtration methods from having to deal with large, more abrasive particles later on.

6. What is called when several cyclone separators are operated parallely?
a) Octa-cyclone
b) Multi-cyclone
c) Center-cyclone
d) Para-cyclone

View Answer

Answer: b [Reason:] When several cyclone operators are operated parallely, when this system is setup it is called multi-cyclone. It is important to note that cyclones can vary drastically in their size. The size of the cyclone depends largely on how much flue gas must be filtered, and thus larger operations tend to need larger cyclones.

7. What is the range of particulate removing efficiency of cyclone separators?
a) 50-99%
b) 20-80%
c) 70-90%
d) 70-95%

View Answer

Answer: a [Reason:] Cyclone separators are generally able to remove somewhere in the range of 50-99% of all particulate matter. How well the cyclone separators are actually able to remove this matter depends largely on particle size. If there is large amount of lighter particulate matter, less of these particles are able to be separated out. Because of this, cyclone separators work best on flue gases that contain large amounts of big particulate matter.

8. What is Baghouse?
a) Filters arranged in parallel form
b) Filters arranged throughout the system
c) Filters arranged randomly
d) Filters arranged alternatively

View Answer

Answer: a [Reason:] A fabric filter element made up of a long hollow cylindrical tube, that provides a large surface per unit of gas volumetric flow rate is called as baghouse filter and a system consisting of large number of such filter elements arranged in parallel rows is called a baghouse.

9. What is the work of the baghouse filter?
a) To remove the hot air from furnace
b) To separate the solid particles from dust produced
c) To remove dust particles from flue gas
d) To wash away the contamination of dust on the walls of furnace

View Answer

Answer: c [Reason:] Baghouse filters are used to remove dust particles from the flue gas produced from the combustion in boiler. These are also called as fabric filters or fabric dust collectors, designed to use fabric filter tubes, envelopes or cartridges to capture or separate dust and particulate matter when the gas is made to pass through the voids.

10. What is the use of wet scrubber in the dust collection?
a) Remove flue gas
b) Remove Scales on the furnace surface
c) Remove the dust that has the moisture content
d) Remove pollutants

View Answer

Answer: d [Reason:] Wet scrubber is used remove the pollutants. The polluted gas stream is brought into contact with the scrubbing liquid, by spraying it with the liquid, by a pool of liquid, or by some other contact method, so as to remove the pollutants.

Set 2

1. Apart from geographical location, the amount of power generated in a country depends on ___________
a) Number of power producing plants
b) Annual consumption of power
c) Utilization of natural resources
d) Quantity of requirement

View Answer

Answer: c [Reason:] Since most of the power produced is from the natural resources, the estimation of amount of power generated in a country is made by the utilization of its natural resources. The ‘Annual consumption of power ‘would give you the details of power utilized for necessities, it is the amount of power utilized out of wholesome amount of total power produced in the country.

2. Total power generated is usually contributed by power generated through ____________
a) Hydel power plant, Thermal power plant and solar plant
b) Ocean thermal energy, Wind energy and Hydel power plant
c) Hydel power plant, Geo-thermal plant and Nuclear power plant
d) Hydel power plant, Thermal power plant and nuclear power plant

View Answer

Answer: d [Reason:] The energy or power produced from hydel power plant, thermal power plant and nuclear power plant is very abundant compared to any other combinations of power producing plants. All these three plants have ability to produce the power in thousands of megawatts in its own standards.

3. On what factors does hydel plant entirely depend?
a) Vegetation
b) Tropical cycle
c) Amount of Rainfall
d) Hydrological cycle

View Answer

Answer: d [Reason:] Hydrological cycle is explanation of continuous movement of water above and below earth surface, where as rainfall is not reliable since it varies period to period. The amount of water above the earth surface and below the earth surface, both are responsible for the hydrological cycle. ‘Vegetation’ is info about the assemblage of plant species irrespective of their geographic characteristics.

4. The steam power plant serves as a base plant for ________
a) Nuclear power plant
b) Geothermal power plant
c) Thermal power plant
d) Diesel plant

View Answer

Answer: a [Reason:] Since power is generated by nuclear power plant and the nuclear plant needs power to perform its operations. For this purpose steam power plant is used as base power plant to generate this power. The power produced base plant acts as a fuel to run the nuclear power plant. And all the cost estimation to produce the electricity is made by considering base load expenses too.

5. What is the primary objective of steam power plant?
a) To convert one form of energy into another form
b) To produce electricity
c) To provide employment
d) To serve as a base load plant to hydel plant or nuclear plant

View Answer

Answer: b [Reason:] The primary objective of steam power plant is to produce electricity and then serving as base load plant to hydel or nuclear power plant comes as second priority. Steam power plants produce 86% of electricity. And the efficiency of steam power plant is typically 33%-48%.

6. A steam power plant works on ___________ cycle.
a) Otto
b) Brayton
c) Hydrological
d) Rankine

View Answer

Answer: d [Reason:] Rankine cycle is a thermodynamic cycle of constant pressure engine that is to convert heat energy into mechanical work and from that following parts like adjoined blades and shafts are made to run to produce electricity. Otto cycle is used in automobile engine and Brayton cycle is used in heat engines & air jet engine.

7. Coal crushers are also known as__________
a) Lather
b) Coal combers
c) Feeder breakers
d) Coal washer

View Answer

Answer: c [Reason:] Coal crushers are also known as feeder breakers, since it is elaborated by word itself. ‘Feeder’ depicts the following component coal being fed by the hoppers and ‘Breaker’ stands for breaking off into smaller pieces. And this synonym is rarely used.

8. Road transportation of coal is preferred for what type of usage?
a) Small capacity plant
b) Medium capacity plant
c) Large capacity plant
d) Domestic usage areas

View Answer

Answer: a [Reason:] Road transportation of coal is ideal transporting coal directly to point of consumption. These small capacity plants are usually located in the middle of land. Trucks and tippers are used to supply coal for this purpose. And also when the plant doesn’t has railway or shipway accessibility in such areas roadways are only possible means of transportation.

9. Which is the more economical way of transporting coal?
a) Sea or River ways
b) Railways
c) Road transporting
d) By Airlifting

View Answer

Answer: b [Reason:] We do know shipways are cheaper. But we need another mode of transport to transfer that coal to the plant area. But in case of railways the tracks can be made to directly pass through the plant. Hence the railway is more economical compared to any other means of transport.

Set 3

1. In which of the following process are Neutrons emitted?
a) Inverse beta Decay
b) Nuclear fission
c) Spontaneous Fission
d) Nuclear fusion

View Answer

Answer: b [Reason:] Nuclear fission is the process in which a heavy nucleus is split into two or more lighter nuclei. This result in decrease in mass and consequent exothermic energy and emission of neutrons take place. Two to three neutrons are emitted per nucleuses which are known as fission elements.

2. Heavy nuclei must be such that they can be fissioned by neutrons of an energy such substance are called?
a) Fission fragments
b) Fission Neutrons
c) Fission species
d) Fission elements

View Answer

Answer: c [Reason:] Heavy nuclei must be such that they can be fissioned by neutrons of energy such substance are called Fission species. All fission species should have long half lives so that the rate of decay is not so fast.

3. Why neutrons with lower energy should be capable of causing fission?
a) For faster reaction process
b) For sustained reaction process
c) For Safety purpose
d) In order to not waste the nuclear fuel

View Answer

Answer: b [Reason:] Due to collisions with various nuclei, initial high kinetic energy of fission neutron decreases. Thus for a sustained reaction, eve neutrons with lower energy should be capable of causing fission. Only neutrons can result in sustained reaction as two or three neutrons are released for each one absorbed by fission.

4. What happens when a neutron is absorbed by a nucleus of an atom of U235?
a) Mass number of atom increases
b) One electron is let out
c) U236 isotope is formed
d) Nucleus becomes unstable

View Answer

Answer: c [Reason:] When a neutron is absorbed by a nucleus of an atom U235, a U236 isotope is formed. This isotope is highly unstable which lasts for one millionth of a second and splits into two equal parts releasing energy of 200MeV.

5. Who invented nuclear fission?
a) Rutherford
b) Hans Bethe
c) Otto Hahn
d) Marie Curie

View Answer

Answer: c [Reason:] Nuclear fission of heavy metals was discovered by German Otto Hahn on December 17, 1938 and was explained theoretically by Lise Meitner and her nephew Otto Robert Frisch on 1939. Frisch named Frisch names the process by analogy with biological fission of living cells.

6. Atoms of different chemical elements that have the same number of nucleons are called as?
a) Isobars
b) Isotones
c) Isomers
d) Isotopes

View Answer

Answer: a [Reason:] Atoms of different chemical elements that have the same number of nucleons are called as isobars. The term isobar was suggested by Alfred Walter Stewart in 1918. It is derived from Greek word ‘isos’ meaning EQUAL and ‘baros’ meaning WEIGHT.

7. Most of the energy released in fission process is in process of __________
a) Kinetic Energy
b) Thermal Energy
c) Light Energy
d) Heat Energy

View Answer

Answer: a [Reason:] Most of the energy released is in the form of kinetic energy and is absorbed by fission products. The fission products formed are fission fragments, neutrons and electromagnetic or gamma radiation. As the fragments collide, the kinetic energy is converted into heat energy.

8. Combining of two light nuclei of low mass to produce a heavy nucleus is called ___________
a) Nuclear fusion
b) Nuclear fission
c) Spontaneous fission
d) Double beta decay

View Answer

Answer: a [Reason:] Nuclear fusion is the process which involves fusion of two light nuclei of low mass to produce a heavy nucleus which results in decrease of mass and release of enormous amount of energy. All atomic bombs prefer nuclear fission process.

9. What type of Reaction takes place in sun?
a) Nuclear fusion
b) Nuclear fission
c) Spontaneous fission
d) Double beta decay

View Answer

Answer: a [Reason:] Nuclear fusion reaction takes place in sun as well as stars. The process is carried by proton-proton chain. The sun starts with protons, and through a series of steps, turns them into helium. Every second 600 million tons of hydrogen is converted into helium. The reaction releases tremendous amount of heat and energy.

10. How many number of nuclei of hydrogen fuse in a series of reaction involving other particles that continually appear and disappear?
a) 1
b) 2
c) 3
d) 4

View Answer

Answer: d [Reason:] Four nuclei of hydrogen fuse in a series of reaction involving other particles that continually appear and disappear such as He3, nitrogen, carbon and other nuclei. 41H12He4 + 2+1e0 (Positrons) Mass decreases to about 0.0276amu releasing 25.7MeV. The heat liberated during this result in temperature of the order of the million degrees and sustains the succeeding reactions.

11. Why is it necessary to accelerate positively charged nuclei to high kinetic energies to cause fusion?
a) To overcome electrical repulsive forces
b) To result in high amount of energy in short period of time
c) To get the isobars and isotopes
d) TO get a sustainable reaction

View Answer

Answer: a [Reason:] To cause fusion, it is necessary to accelerate positively charged nuclei to high kinetic energies to overcome electrical repulsive forces. This is done by rising their temperatures to hundreds of millions of degree resulting in plasma.

12. Fusion reactions are called __________
a) Thermonuclear
b) Thermoduric
c) Thermo Uric
d) Compound reactions

View Answer

Answer: a [Reason:] To eradicate repulsive forces temperature of positively charged nuclei is raised to millions of degree resulting in plasma. The plasma should be prevented from contacting the walls of the container confined for a period of time of the order of a second at a minimum density. Fusion reactions are called thermonuclear because of the higher temperature requirement to trigger and sustain the reaction.

13. Which of the following element is readily available in the ordinary water?
a) Cesium
b) Thorium
c) Deuterium
d) Astatine

View Answer

Answer: c [Reason:] Deuterium used in fusion reaction is readily available in ordinary water (Out of 6500 molecules). Deuterium is also known as heavy hydrogen. The nucleus of deuterium is called as deuteron, Contains one proton and one neutron.

14. How is tritium made from sea water?
a) By bombarding lithium
b) By bonding with carbon
c) By bombarding Beryllium
d) By reacting with oxygen

View Answer

Answer: a [Reason:] Tritium is made by seawater by bombarding with lithium. Lithium is a chemical element with Atomic number: 3 and Mass number: 6.941 u ± 0.002 u. Because of its relative nuclear instability, lithium is less common in the solar system.

Set 4

1. Which nuclear fuel is usually used in thermal nuclear reactor to create fission?
a) U234
b) U235
c) U236
d) U237

View Answer

Answer: b [Reason:] In a thermal nuclear reactor the fission induced by neutrons using a fuel isotope U235 is one of the several isotopes used in nuclear power generation. Fuel isotopes which are capable of being fissioned by thermal neutrons are called fissile’s.

2. 90Th232 is fertile isotope produced by fission?
a) True
b) False

View Answer

Answer: a [Reason:] 90Th232 is a fertile isotope produced by nuclear fission. 90Th has 6 naturally occurring isotopes, none of these isotopes are stable; however, one isotope, 232Th is relatively stable, with a half life of 1.405× 1010 years, considerably longer than the age of earth.

3. Which parts function is to reduce the energy of fast neutrons to thermal neutrons in nuclear power plant?
a) Moderator
b) Coolant circulator
c) Control rods
d) Shielding

View Answer

Answer: a [Reason:] Function of moderator is to reduce the energy of fast neutrons to thermal neutrons. Due to high energy of fission neutrons relative to that required to trigger another fission event their probability of interacting with U235 is small.

4. What makes the best moderators in nuclear power plant?
a) Material with low atomic number
b) Materials with low atomic mass
c) Materials with high atomic number
d) Materials with high mass number

View Answer

Answer: a [Reason:] The moderator slows down the neutrons to thermal energies by collision with inert atoms (scattering). Speed of the neutrons is reduced within a small number of collisions as the moderator possesses a high scattering cross section. Materials with low atomic mass number make best moderators.

5. Select the desirable property of a moderator?
a) Moderator should absorb neutrons but slow down the neutrons as early as possible
b) It should have low thermal conductivity for better heat transfer
c) It shouldn’t be chemically unstable
d) It should have low resistance to corrosion

View Answer

Answer: c [Reason:] It should be chemically stable and should not e decomposed due to nuclear radiation. It should not absorb neutrons but slow down the neutrons as early as possible. It should have high resistance to corrosion as it has to work under high pressure and temperature.

6. What is used in nuclear reactor as a cooling method/device?
a) Coolant
b) Water jackets
c) Air cooler
d) Air vents

View Answer

Answer: a [Reason:] The coolant is used and its function is to remove the heat released by fission. The coolant should have high specific heat, high conductivity, good chemical stability, good pumping characteristics and low neutron absorption cross section. Coolant can either be liquid or gas.

7. Control rods are made of __________
a) Cesium
b) Cadmium
c) Tin
d) Gallium

View Answer

Answer: b [Reason:] Control rods are made of cadmium or boron or Hafnium. They have huge neutron absorption cross sections. The control rods are lowered or raised in the reactor core. Control rods are used in control rod assemblies and inserted into the guide fuels within a fuel element.

8. Reactor power is directly proportional to neutron density?
a) True
b) False

View Answer

Answer: a [Reason:] Reactor power is directly proportional to neutron density, lowering the control rods will remove neutron from the reactor core and will decrease the power and reaction rate and raising the control rods will increase the power and rate.

9. What types of rays are trapped by shielding?
a) Gamma rays
b) Beta rays
c) X-rays
d) IR rays

View Answer

Answer: a [Reason:] Shielding prevents the passage of radiation to the outside of the reactor. The primary shield prevents the leakage of neutron and gamma radiation present in the cooling circuits due to activation of coolant as passes through the core.

10. Shield is made of _________
a) Iron Metal enclosure
b) Concrete and water
c) Ceramics walls
d) Copper metal

View Answer

Answer: b [Reason:] Shield is frequently constructed in layers or heavy and light material like concrete and water. Shields for external circuit where only gamma radiation may be present is made up of steel, lead, polyethylene, concrete.

11. Which of the following part in a nuclear reactor minimizes the neutron leakage?
a) Shield
b) Control rods
c) Reflector
d) Moderator

View Answer

Answer: c [Reason:] Function of the reflector is to minimize the neutron leakage by reflecting them back into the reactor. The material used for reflector is same as that used for moderator. It scatters the neutrons that leak from core and returns the neutrons back into core by reflecting them.

12. In which of the following reactor is fission caused by slow or thermal neutrons?
a) Thermal reactor
b) Burner reactor
c) Fast reactor
d) Breeder reactor

View Answer

Answer: a [Reason:] A thermal reactor is a nuclear reactor that uses slow or thermal neutrons. Most nuclear power plants are thermal reactors and use neutron moderator to slow neutrons until they approach the average kinetic energy of the surrounding particles. Fission is caused by slow or thermal neutrons.

13. Which reactor has no moderator and its core size is less?
a) Fast reactor
b) Burner reactor
c) Thermal reactor
d) Breeder reactor

View Answer

Answer: a [Reason:] A fast reactor is a category of nuclear reactor in which the fission chain reaction is sustained by fast neutrons, as opposed to thermal neutrons used in thermal neutron reactors. The fission process is caused by fast neutrons and the reactor has no moderator and the core size less.

14. In which reactor is fertile material converted into initial fissile material?
a) Breeder reactor
b) Fast reactor
c) Burner reactor
d) Thermal reactor

View Answer

Answer: a [Reason:] A breeder reactor is a nuclear reactor that generates more fissile material than it consumes. In this reactor fertile material is converted into initial fissile material. For e.g. natural uranium is the fuel, thorium is converted into U233.

15. Which reactor produces only heat?
a) Burner reactor
b) Breeder reactor
c) Thermal reactor
d) Intermediate reactor

View Answer

Answer: a [Reason:] Burner reactor is a type of reactor using U235 as fuel. Enriched uranium is used to increase efficiency. To prolong the fission reaction, fast neutrons are slowed down with a moderator and the rate of reaction is adjusted by control rods which can absorb neutrons. Some neutrons react to form plutonium, but in smaller amounts than the original uranium, and produces only heat as a product.

Set 5

1. Which is the type of energy where the energy is harnessed by the heat accumulated on the surface of water?
a) Wind energy
b) Wave energy
c) Ocean thermal energy conversion
d) Solar energy

View Answer

Answer: c [Reason:] Absorption of heat from the sun by the seas and oceans, solar radiation causes ocean currents and moderate temperature gradients from the water surface downward especially in tropical waters.

2. Water _________ decreases with an increase in temperature.
a) volume
b) density
c) pressure
d) force

View Answer

Answer: b [Reason:] Water density decreases with an increase in temperature. Thus, there will be no thermal convection currents between the warmer, lighter water at the top and the deep cooler, heavier water. Thermal conduction heat transfer between them, across the large depths, is too low and thus mixing is retarded, so the warm water stays at the top and cool water stays at the bottom.

3. How many essentially infinite heat reservoirs are present in tropical waters?
a) 1
b) 2
c) 3
d) 4

View Answer

Answer: b [Reason:] In tropical waters, there are two essentially infinite heat reservoirs, a heat source at the surface at about 27oC and heat sink some 1 Km directly below, at about 4oC, both reservoirs are maintained by solar incidence.

4. Who first recognized the OTEC?
a) d’Arsonval
b) Alexander Edmond Becquerel
c) James Prescott joule
d) LA Rance

View Answer

Answer: a [Reason:] The concept of ocean temperature energy conversion is based on the utilization of temperature difference in a heat engine to generate power. It was first recognized by Frenchman d’Arsonval in the year 1881.

5. From which cycle does maximum possible efficiency of a heat engine operating between two temperature limits cannot exceed?
a) Carnot cycle
b) Otto cycle
c) Open cycle
d) Anderson cycle

View Answer

Answer: a [Reason:] The maximum possible efficiency of a heat engine operating between two temperature limits cannot exceed that of a Carnot cycle operating between the same temperature limits. The Carnot efficiency is given by ηc = (T1-T2 )/T1.

6. Which of the following has the lowest efficiency?
a) Solar energy
b) Wind energy
c) Wave energy
d) OTEC

View Answer

Answer: d [Reason:] OTEC power generation gives less efficiency. However, because of the OTEC requirement for parasitic power and other losses, the achievable net conversion efficiencies of 30 to 40% associated with conventional power plants.

7. The Claude cycle is also called as __________
a) Open cycle
b) Anderson cycle
c) Closed cycle
d) Otto cycle

View Answer

Answer: a [Reason:] A Claude cycle is also called as open cycle in which sea water itself plays, the multiple role of heat source, working fluid and heat sink. In this cycle warm water at 27oC is admitted into an evaporator in which the pressure is maintained at a value slightly below the saturation pressure corresponding to that of water temperature.

8. Anderson cycle is also known as _________
a) Open cycle
b) Claude cycle
c) Closed cycle
d) Otto cycle

View Answer

Answer: c [Reason:] Anderson cycle is also called as closed cycle. Closed cycle utilizes the oceans warm surface and cool deep waters heat source and sink respectively, but requires a separate working fluid that receives and rejects heat to the source and sink via heat exchanges.

9. Who proposed closed cycle approach?
a) Barjot
b) Alexander Edmond Becquerel
c) James Prescott joule
d) LA Rance

View Answer

Answer: a [Reason:] The closed cycle approach was first proposed by Bajrot in 1926, but the most recent design was by Anderson in 1960s. The closed cycle is sometimes referred to as Anderson cycle. The Anderson cycle chose Propane as working fluid.

10. The working fluid chosen by Anderson OTEC cycle is ______
a) Propane
b) Water
c) Engine oil
d) ISO-butane

View Answer

Answer: a [Reason:] The working fluid chosen by Anderson OTEC cycle is propane. The operating pressures of such fluid at the boiler condenser temperatures are much higher than those of water being roughly 10 bars at the boiler, and their specific volumes are much lower, being comparable to those of steam in conventional power plants.

11. Which is the working fluid in open cycle?
a) Propane
b) Water
c) Engine oil
d) ISO-butane

View Answer

Answer: b [Reason:] In the open/Claude cycle, water is the working fluid. The warm water surface water is caused to boil by lowering the pressure, without supplying any additional heat. The low pressure steam produced then, drive’s the turbine and the exhaust steam is condensed by the deep colder water is discarded.

12. A continuous movement of water in specific direction is called as _________
a) float
b) waves
c) current
d) tides

View Answer

Answer: d [Reason:] Water currents can be found in streams, rivers and oceans throughout the world. Water current is the rate of movement in the water, and ways to describe water current include its speed and direction. There are different types of water currents which behave in different ways because they are affected by separate variables.