McqMate
These multiple-choice questions (MCQs) are designed to enhance your knowledge and understanding in the following areas: Mechanical Engineering .
| 101. |
Nuclear energy is only harmful. |
| A. | true |
| B. | false |
| Answer» B. false | |
| Explanation: nuclear energy can be both beneficial and harmful, depending on the way in which it is used. for example x-rays which are used to examine bone fracture is useful. | |
| 102. |
Which State in India nuclear accident took place? |
| A. | tamil nadu |
| B. | karnataka |
| C. | gujarat |
| D. | rajasthan |
| Answer» A. tamil nadu | |
| Explanation: a small amount of nuclear accident observed in the villages and towns around the kalpakkam nuclear station, south of chennai in tamil nadu, in an ongoing study by pugazhendi. it was took place in january 2003. | |
| 103. |
Which one of the following medical condition caused by the high exposure of radiation? |
| A. | kidney stone |
| B. | aids |
| C. | mutation |
| D. | blood pressure |
| Answer» C. mutation | |
| Explanation: excessive exposure to the radiations leads to mutation, which are changes in the genetic makeup of the cells. mutations can occur in the tissues of the body and may manifest themselves as abnormal tissue growth known as cancer. | |
| 104. |
What is the main purpose of nuclear energy? |
| A. | to kill the enemy nation |
| B. | to waste the excessive energy |
| C. | to use it as an alternate source of energy |
| D. | to cause mutation for people who are working |
| Answer» C. to use it as an alternate source of energy | |
| Explanation: nuclear energy was developed by man as an alternate source of clean and cheap energy when compared to fossil fuels. along with the benefits of nuclear energy, there have been a number of accidents which harm many lives. | |
| 105. |
Approximately how many percentage of electricity produced by nuclear power in the world? |
| A. | 10 |
| B. | 14 |
| C. | 17 |
| D. | 20 |
| Answer» C. 17 | |
| Explanation: approximately 17% of electricity produced by nuclear power in the world. nuclear power is being used worldwide for the generations of electricity. with numerous harm effects of nuclear power the main advantage is to produce electricity from nuclear power. | |
| 106. |
The use of nuclear energy in the war had devastating effects on humans and on the earth. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: during war nuclear power is used only once so far. the united states dropped two atomic bombs over the japanese towns of hiroshima and nagasaki in 1945. | |
| 107. |
Spillway discharges the overflow water to the downstream side when the reservoir is full. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: a condition may arise during flood periods when water level increases beyond the capacity of reservoir. in such conditions spillway acts as safety valve. | |
| 108. |
Trash racks are built for |
| A. | discharging the water freely from the turbine exit to tailrace |
| B. | preventing the turbine from ingress of floating and other materials |
| C. | creating artificial head to store sufficient potential energy of water |
| D. | controlling the opening of valves |
| Answer» B. preventing the turbine from ingress of floating and other materials | |
| Explanation: heavy solid materials flowing with water can damage the turbine blades if not stopped. trash racks are closely spaced flat bars which provides narrow path from which such unwanted materials cannot pass. | |
| 109. |
Penstock in a hydroelectric power plant is |
| A. | a pipe connected to runner outlet |
| B. | nozzle that release high pressure water on turbine blades |
| C. | a conduit connecting forebay to scroll case of turbine |
| D. | a pipe connecting surge tank to dam |
| Answer» C. a conduit connecting forebay to scroll case of turbine | |
| Explanation: penstocks are the conduit built of steel or reinforced concrete. penstock | |
| 110. |
The pressure at the inlet or exit of the draft tube should not be |
| A. | less than one third of atmospheric pressure |
| B. | greater than one third of atmospheric pressure |
| C. | less than one atmospheric pressure |
| D. | greater than one atmospheric pressure |
| Answer» A. less than one third of atmospheric pressure | |
| Explanation: decrease in pressure in any portion of turbine below one third of atmospheric pressure may cause vapour bubbles or cavities to form. this phenomenon is called cavitation. also to maintain continuity of flow without vaporisation the pressure should not fall below vapour | |
| 111. |
Draft tube increases the operating head on the turbine. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: draft tubes are the pipes of suitable diameter attached to the runner outlet. draft tube converts the pressure developed by water leaving from turbine into kinetic energy. this in turn increases the operating head on turbine. | |
| 112. |
Trash racks are located |
| A. | near tailrace |
| B. | at the entrance of turbine |
| C. | inside penstock |
| D. | intake |
| Answer» D. intake | |
| Explanation: intake includes headworks at the entrance of conduit. those headworks include different structures, trash racks are one of them. trash racks are fitted directly at the intake to prevent the floating and other materials from going into the conduit. | |
| 113. |
What is the function of booms? |
| A. | it supports the dam |
| B. | it supports the penstock |
| C. | it divert the icebergs from flowing into the penstock |
| D. | to hold the turbine structure |
| Answer» A. it supports the dam | |
| Explanation: booms are the one of those structures made at the intake. they are constructed to prevent unwanted solid materials from flowing into the penstock. solid materials like icebergs, wood logs or other heavy materials which may cause damage to the turbine blades if reached there. | |
| 114. |
How much is the average temperature at depth of 10 km of earth surface? |
| A. | 200oc |
| B. | 900oc |
| C. | 650oc |
| D. | 20oc |
| Answer» A. 200oc | |
| Explanation: the heat is apparent from the increase in temperature of the earth with increasing depth below the surface. although higher and lower temperature occurs, the average temperature at depth of 10 km is about 200oc. | |
| 115. |
What is hot molten rock called? |
| A. | lava |
| B. | magma |
| C. | igneous rocks |
| D. | volcano |
| Answer» B. magma | |
| Explanation: magma is a mixture of molten or semi-molten rock, volatiles and solid that is found beneath the surface of the earth, and | |
| 116. |
What does EGS stand for in geothermal energy? |
| A. | engraved geothermal systems |
| B. | enhanced geothermal system |
| C. | exhaust gas system |
| D. | engineered geo physical system |
| Answer» B. enhanced geothermal system | |
| Explanation: the development of a geothermal system where hydraulic fracturing of the system can allow the production at a commercial level. egs’s are engineered reservoirs created where there is geothermal energy but a lack of permeability. fluid is injected into the earth‘s surface which causes pre-existing fractures to open again, creating permeability. nationwide potential with engineered reservoirs 6-km to 8-km deep. | |
| 117. |
Who invented first geothermal plant? |
| A. | michael faraday |
| B. | piero ginori conti |
| C. | enrico fermi |
| D. | guglielmo marconi |
| Answer» B. piero ginori conti | |
| Explanation: in 1904, italian scientist piero ginori conti invented the first geothermal electric power plant in which steam was used to generate the power. on 4 july 1904, at larderello, piero ginori conti powered five bulbs from a dynamo driven by a | |
| 118. |
A geothermal solution containing appreciable amounts of sodium chloride or other salts is called as |
| A. | fluids |
| B. | brine |
| C. | solvent |
| D. | magma |
| Answer» B. brine | |
| Explanation: brine is a high-concentration solution of salt (usually sodium chloride) in water. in different contexts, brine may refer to salt solutions ranging from about 3.5% (a typical concentration of seawater, on the lower end of solutions used for brining foods) up to about 26% (a typical saturated solution, depending on temperature). | |
| 119. |
Earth’s outer layer rock is called as |
| A. | mantle |
| B. | crust |
| C. | outer core |
| D. | asthenosphere |
| Answer» B. crust | |
| Explanation: earth’s crust is earth’s hard outer layer. it is less than 1% of earth’s volume. the crust is made up of different types of rocks: igneous, metamorphic, and sedimentary rocks. crust is also called as lithosphere. | |
| 120. |
The hole on earth’s surface from where the steam from the earth comes out is called as |
| A. | gash |
| B. | mud pot |
| C. | void |
| D. | fumarole |
| Answer» D. fumarole | |
| Explanation: a fumarole is an opening in a planet’s crust, often in areas surrounding volcanoes, which emits steam and gases such | |
| 121. |
A spring that shoots jets of hot water and steam into the air is called as |
| A. | mine hole |
| B. | geyser |
| C. | hot spring |
| D. | mud pot |
| Answer» B. geyser | |
| Explanation: geysers are temporary | |
| 122. |
Which kind geothermal plant is most common type? |
| A. | dry steam |
| B. | flash |
| C. | binary |
| D. | wet steam |
| Answer» B. flash | |
| Explanation: flash steam power plants are the most common form of geothermal power plant. the hot water is pumped under great pressure to the surface. when it reaches the surface the pressure is reduced and as a result some of the water changes to steam. this produces a ‘blast’ of steam. the cooled water is returned to the reservoir to be heated by geothermal rocks again. | |
| 123. |
How much is the efficiency of geothermal plant? |
| A. | 28% |
| B. | 15% |
| C. | 42% |
| D. | 30% |
| Answer» B. 15% | |
| Explanation: geothermal power plants have lower efficiency relative to other thermal power plants, such as coal, natural gas, oil, and nuclear power stations. it is commonly assumed that only 15% of the energy from the produced geothermal fluid can be converted | |
| 124. |
The area under the load curve represents |
| A. | the average load on power system |
| B. | maximum demand |
| C. | number of units generated |
| D. | load factor |
| Answer» C. number of units generated | |
| Explanation: load curve is obtained by plotting fluctuating load be keeping load on y axis and time in x axis. the area under the load curve represents the total number of units generated in a particular time. | |
| 125. |
Which of the following is equal to the maximum demand? |
| A. | the ratio of area under curve to the total area of rectangle |
| B. | the ratio of area under curve and number of hours |
| C. | the peak of the load curve |
| D. | the area under the curve |
| Answer» C. the peak of the load curve | |
| Explanation: the ratio of area under curve to the total area of the rectangle is called load factor. the ratio of area under the curve to the number of hours represents the average load. the peak of the curve represents the maximum demand. | |
| 126. |
Load duration curve indicates |
| A. | the variation of load during different hours of the day |
| B. | total number of units generated for the given demand |
| C. | total energy consumed by the load |
| D. | the number of hours for which the particular load lasts during a day |
| Answer» D. the number of hours for which the particular load lasts during a day | |
| Explanation: the variation of load during different hours of the day is shown by load curve. load duration curve is different from load curve. load duration curve indicates the variation of the load, but with the load arranged in descending order of magnitude. | |
| 127. |
During which time the demand of electrical energy is maximum? |
| A. | 2 a.m. to 5 a.m. |
| B. | 5 a.m. to 12 p.m. |
| C. | 12 p.m. to 7 p.m. |
| D. | 7 p.m. to 9 p.m |
| Answer» D. 7 p.m. to 9 p.m | |
| Explanation: from the load curve it is obtained that during early morning demand is always low. around 5 a.m. it starts increasing and around 9 a.m. load reaches a high value and remains almost constant till evening except for some dip during lunch hours. the load again starts increasing in evening hours and reaches its peak around 7 to 9 p.m. | |
| 128. |
Size and cost of installation depends upon |
| A. | average load |
| B. | maximum demand |
| C. | square mean load |
| D. | square of peak load |
| Answer» B. maximum demand | |
| Explanation: the greatest of all “short time interval averaged” during a given period, on the power system is called the maximum demand. maximum demand represents the maximum amount of load that is active, out of total connected load. so the size and rating of power plant depends on maximum demand. | |
| 129. |
What is Demand factor? |
| A. | ratio of connected load to maximum demand |
| B. | ratio of average load to connected load |
| C. | ratio of maximum demand to the connected load |
| D. | ratio of kilowatt hour consumed to 24 hours |
| Answer» C. ratio of maximum demand to the connected load | |
| Explanation: demand factor is the ratio of actual maximum demand on the system to the total load connected to the system. the idea of demand factor was introduced due to the fact that all the equipments connected to the | |
| 130. |
The load factor is |
| A. | always less than unity |
| B. | less than or greater than 1 |
| C. | always greater than 1 |
| D. | less than zero |
| Answer» A. always less than unity | |
| Explanation: load factor is the ratio of average demand to the maximum demand. average demand can not be greater than maximum demand. so the value of load factor is always less than unity. | |
| 131. |
In practice what is the value of diversity factor? |
| A. | less than unity |
| B. | geater than unity |
| C. | equal to or greater than unity |
| D. | less than zero |
| Answer» B. geater than unity | |
| Explanation: maximum demand of different consumers never occurs at a time, due to this the total maximum demand of the load is always less than sum of individual maximum | |
| 132. |
Which of the following is called as cold reserve? |
| A. | reserve capacity available but not ready for use |
| B. | reserve capacity available and ready for use |
| C. | generating capacity connected to bus and ready to take load |
| D. | capacity in service in excess of peak load |
| Answer» A. reserve capacity available but not ready for use | |
| Explanation: cold reserve is the generating capacity which is available for service but not normally ready for immediate loading. | |
| 133. |
How are moderate active solid wastes disposed? |
| A. | buried underground |
| B. | buried under sea |
| C. | sent to outer space |
| D. | left out in streams or rivers |
| Answer» A. buried underground | |
| Explanation: in a nuclear fuel cycle, the solid, liquid and gaseous radioactive wastes are produced at different stages. these radioactive wastes must be disposed off in such a manner that there is no hazard to the human and plant life. moderate active solid wastes are buried in the ground. | |
| 134. |
Moderate liquid nuclear wastes are disposed into |
| A. | deep pits |
| B. | buried underground |
| C. | left into rivers |
| D. | left into deep oceans |
| Answer» A. deep pits | |
| Explanation: moderate liquid wastes after preliminary treatments are discharged in deep pits or day well from which they sweep out into the surrounding. certainly liquid wastes are mixed with some kind of other chemical in order to lower their radioactivity. | |
| 135. |
How are active liquids of nuclear waste disposed? |
| A. | stored in concrete tanks and buried underground |
| B. | stored in concrete tanks and buried in sea |
| C. | mixed with other chemicals and left into free atmosphere |
| D. | they are reused and burnt away in gaseous fumes |
| Answer» A. stored in concrete tanks and buried underground | |
| Explanation: active liquids are kept in concrete tanks and these tanks are buried in the ground till their decay of radio activity. many times the radio activity increases the temperature of the liquid waste or sometimes these liquids boil and the activity decreases with time. | |
| 136. |
Can vacated coal mines be used for waste disposal. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: yes, vacated coal mines can be used for waste disposal. the wastes are disposed in the salt heaps provided in the mines, because salt is a powerful absorber of radioactive emissions. it will be easy and more economical method to dispose of liquid waste by freezing. | |
| 137. |
How is High Level solidified nuclear wastes (HLW) stored? |
| A. | concrete tanks |
| B. | canisters |
| C. | packed rock salt |
| D. | soil bins |
| Answer» B. canisters | |
| Explanation: the solidified waste is placed in canisters that are stored in holes formation | |
| 138. |
Absorption of radioactive element by human, affects their offspring’s. |
| A. | true |
| B. | false |
| Answer» A. true | |
| Explanation: absorption of neutron or radioactive element by a tissue nucleus leads to radioactive nucleus which results change in chemical nature, mal-functioning of cell. due to this, cell damages leading to genetic modification. inhale of radioactive material through air, food and water result radiation hazard. | |
| 139. |
For how many days is radioactive solid waste kept is kept under water at 6m deep for initial cooling? |
| A. | 15 days |
| B. | 50 days |
| C. | 30 days |
| D. | 100 days |
| Answer» D. 100 days | |
| Explanation: it is necessary to keep the radioactive solid waste first in the water of 6m depth nearly for 100 days. it was found that after 100 days cooling of radioactive waste of 28mw plant in water still has a radioactivity equal to million grams of radium. about 50% radioactive elements disappear during cooling. | |
| 140. |
What are released into biosphere from nuclear power plants? |
| A. | gaseous effluents |
| B. | waste product |
| C. | smoke |
| D. | the obtained product |
| Answer» A. gaseous effluents | |
| Explanation: under normal operation, gaseous effluents are released slowly from the power plants into the biosphere and become diluted and dispersed harmlessly. releasing at slow rates gives it time to blow of slowly. | |
| 141. |
Tailings forms are the residues from |
| A. | uranium |
| B. | thorium |
| C. | cadmium |
| D. | boron |
| Answer» A. uranium | |
| Explanation: tailings are residues from uranium mining and milling operations. they contain low concentration of naturally occurring radioactive materials. they are generated in large volumes and are stored at the mine or mill sites. | |
| 142. |
LLW stands for |
| A. | low level water |
| B. | low laser width |
| C. | low level waste |
| D. | loss of levels in water |
| Answer» C. low level waste | |
| Explanation: low level waste contains less than 10 nci per gram of transuranium contaminants containing low but potentially hazardous concentrations of radioactive materials. these are generated in almost all activities involving radioactive materials, require little or no shielding. | |
| 143. |
What is the unit of Heat rate? |
| A. | kj/kw |
| B. | kw/kj |
| C. | kj |
| D. | kw |
| Answer» A. kj/kw | |
| 144. |
Rankine efficiency of a Steam Power Plant |
| A. | improves in summer as compared to that in winter |
| B. | improves in winter as compared to that in summer |
| C. | is unaffected by climatic conditions |
| D. | none of the mentioned |
| Answer» B. improves in winter as compared to that in summer | |
| 145. |
Which of the following contributes to the improvement of efficiency of Rankine cycle in a Thermal Power Plant? |
| A. | reheating of steam at intermediate stage |
| B. | regeneration use of steam for heating boiler feed water |
| C. | use of high pressures |
| D. | all of the mentioned |
| Answer» D. all of the mentioned | |
| 146. |
What is the actual turbine inlet temperature in Rankine cycle? |
| A. | 700c |
| B. | 800c |
| C. | 550c |
| D. | 1150c |
| Answer» C. 550c | |
| 147. |
Rankine cycle efficiency of a good Steam Power Plant may be in the range of? |
| A. | 15 to 20% |
| B. | 35 to 45% |
| C. | 70 to 80% |
| D. | 90 to 95% |
| Answer» B. 35 to 45% | |
| 148. |
A simple Rankine cycle produces 40 MW of power, 50 MW of process heat and rejects 60 MW of heat to the surroundings. What is the utilization factor of this co generation cycle neglecting the pump work? |
| A. | 50 |
| B. | 60 |
| C. | 70 |
| D. | 80 |
| Answer» B. 60 | |
| 149. |
Which type of boilers use orifice to control the flow circulation? |
| A. | natural circulation boilers |
| B. | forced convection boilers |
| C. | once-through boilers |
| D. | positive forced circulation boilers |
| Answer» B. forced convection boilers | |
| 150. |
What is the advantage of having smaller ratio of water to steam space? |
| A. | steam can be generated at a faster even if the boiler is cold |
| B. | increases the rate of evaporation |
| C. | water is made cyclic, i.e., from boiler drum to water tube and back to drum |
| D. | helps in mobilizing the boiler |
| Answer» A. steam can be generated at a faster even if the boiler is cold | |
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