Multiple choice question for engineering
1. What do you call a graph which is plotted for discharge versus time?
a) Snow Graph
c) Rain graph
d) Fluid graph
Answer: b [Reason:] The graph showing discharge of flowing water with respect to time for a specific time is known as hydrograph. The time period for discharge hydrograph may be hour, day, week or month. The discharge may m¬¬3/sec or day per second meter.
2. Choose the correct sentence about information available from hydrograph among the following options?
a) The mean annual runoff or mean runoff each week of the year
b) Total volume at that instant, as the area under hydrograph indicates the force of water during the duration
c) Rate of flow at any particular time during the duration period
d) Mean runoff for each month
Answer: d [Reason:] Mean runoff for each month is available. As compared to all other option, they would be- A) The mean annual runoff or mean runoff each month of the year. B) Total volume at that instant, as the area under hydrograph indicates the volume of water during the duration. C) Rate of flow at any instant during the duration period.
3. What does hydrograph based on day gives?
a) Idea about flood period during the month
b) Idea of rainfall
c) Idea of draught during the year
d) Idea of scarcity of water in the upcoming year
Answer: a [Reason:] The hydrograph can be drawn taking day, month or year. The hydrograph on the basis of day gives an idea of the flood period during the month. The hydrograph on basis of month gives an idea about the dry period of the year.
4. What information does the year wise hydrograph gives?
b) Heavy rainfall
c) Rising cold
d) Water scarcity
Answer: a [Reason:] The hydrograph can be drawn taking Day, month or year as time axis. The hydrograph based on year wise data gives information concerning the lean or draught year. This is very essential for deciding the location and size of hydel power plant.
5. When is the Hydrograph called as a unit hydrograph?
a) When 1cm of runoff is resulted from a rain fall
b) When 3cm of runoff is resulted from rainfall
c) When 1mm of runoff is resulted from rainfall
d) When 3mm of runoff is resulted from rainfall
Answer: a [Reason:] If the rainfall distribution in the storms is similar with respect to time and area, the ordinate of each hydrograph will be proportional to volume of runoff. The unit hydrograph is a hydrograph with a volume of 1cm runoff resulting from a rainfall of specified duration and a real pattern.
6. Unit hydrograph was explained by Sherman in which year?
Answer: c [Reason:] This unit hydrograph principle was expressed by Sherman in 1932; he introduced the theory of unit hydrograph. He pointed out that all hydrographs have same time resulting from rainfalls of the given duration.
7. Hydrographs of similar rainfalls will be similar in shape.
Answer: a [Reason:] Hydrographs of various rainfalls will be similar in shape. The ordinates are proportional to the runoff volumes within a fixed duration and similar rate and a real distribution of rainfall. However, the occurrence of identical rainfall is very rare.
8. What is unit hydrograph helpful in?
a) Estimating runoff from a basin
b) Estimating no of days of rain fall
c) Knowing the draught months in a year
d) In deciding the land for hydel power plant
Answer: a [Reason:] Unit hydrograph is helpful in estimating runoff from a basin for a storm of given duration. It is also helpful in predicting the expected flood flow from a catchment if rainfall intensity in the catchment is known.
9. What is the theoretical number of unit hydrographs for given basin?
Answer: d [Reason:] The number of unit hydrographs for a given basin is theoretically infinite. This is because there may be one unit hydrograph for possible duration of rainfall and every possible distribution pattern of rainfall in the basin.
10. Above which range should be the unit hydrographs be used?
a) Around 5000 sq km
b) Over 2500 sq km
c) Around 4000 sq km
d) Below 5000 sq km
Answer: a [Reason:] In practice, only a limited number of unit hydrographs are used for a given basin. It is also common practice to neglect the variations in rainfall distribution within the basin area. Hence it is not advisable to use unit hydrograph method for basins over 5000sq km.
11. The unit hydrographs can be successfully applied to basin areas of what sq km?
a) 15000 sq km
b) 10000 sq km
c) 3000 sq km
d) 25000 sq km
Answer: d [Reason:] The unit hydrographs can be applied successfully to basin areas as large as 25000 sq km. provided distribution patterns are classified into different types and unit hydrographs are developed for each type it is always preferable to divide the large basin into sub-areas, utilize hydrographs for each sub area independently and combine the resulting hydrographs together.
12. The magnitude of runoff as ordinates against the corresponding percentage of time as abscissa gives ________
a) Mass duration curve
b) Load duration curve
c) Power duration curve
d) Flow duration curve
Answer: d [Reason:] The magnitude of runoff as ordinates against the corresponding percentage of time as abscissa gives Flow duration curve. If the magnitude on the ordinate is the potential power contained in the stream flow, then the curve is known as power duration curve.
13. What is DWF?
a) Deep water flow
b) Dry weather flow
c) Drawing web format
d) Dam water flood
Answer: b [Reason:] Dry weather flow is a waste water flow in a sewer system during dry weathers with minimum filtration process while entering the ground. Insufficient flow velocities during DWF can increase retention.
14. What does CN stands for in hydrology?
b) Channel number
d) Carbon nano-tube
Answer: c [Reason:] Cumulonimbus, from the Latin cumulus and nimbus, is a dense, towering vertical cloud associated with thunderstorms and atmospheric instability, forming from water vapor carried by powerful upward air currents.
15. What does ADF stand for in hydrology?
a) Automatic direction finder
b) Average daily flow
c) Average duration flow
d) Annual dry flow
Answer: b [Reason:] The daily effluent flow is required to calculate the area of septic field or the length of trench requires. It is also referred as the amount of water let out of a reservoir on the daily basis as per the requirement and demand.
1. How does Hydro power plays important in development of a country?
a) Shows the amount of water power in a country
b) Providing abundant amount of power
c) Providing power at cheap rate
d) Power production by hydro power plant is easier
Answer: c [Reason:] In the development of a country the hydro power plays a very important role because it provides power at cheapest rates. No raw material is required for the production of power from hydro power plant.
2. How much of the total amount of power developed world wide consists of hydro power plant?
Answer: b [Reason:] Nearly 20% of the total world’s power is generated using hydro power plants. To countries in the world 90% of the nation’s power requirement is met by hydro power. When compared country wise this amount is very high.
3. Which two countries have vast hydro resources?
a) Hungary and Luxemburg
b) India and china
c) Russia and Nepal
d) Japan and Georgia
Answer: c [Reason:] Russia and Nepal have vast hydro resources that are to be harnessed. As per the estimation of world power organization, the world hydro potential is roughly 5000GW whereas only 4% of it (200GW) is presently developed.
4. What type of energy does rain falling holds relative to the oceans?
a) Potential energy
b) Kinematic energy
c) Electrical energy
d) Motion energy
Answer: a [Reason:] Rain falling on earth surface has potential energy relative to oceans towards which it flows. This energy can be converted into shaft work by hydraulic prime mover and finally into electrical energy. The conversion of this energy takes time.
5. The shaft power developed by the water passing through the prime mover is given by _______
Answer: a [Reason:]
Where, m = Rate of water flow in kg/sec.
H = Height of fall in meters.
no = overall efficiency.
6. On what does generation of Hydro power depends?
a) Quantity of water available
b) On capacity of turbine
c) Height of head
d) Storage capacity
Answer: a [Reason:] Generation of power depends on the quantity of water available. The available head depends upon the selection of site for hydraulic power plant. The site of the power plant is always selected for the highest available head when other things are in favor of site selection.
7. On what does the Quantity of water available at selected site depends?
a) Temperature at the selected site
b) Humidity at selected site
c) Vegetation of the area
d) Hydrological cycle of area
Answer: d [Reason:] The quantity of water available at the selected site depends upon the hydrological cycle of nature. The quantity of water available can be determined from the study of rainfall and run off in the area.
8. Capacity of hydraulic plant is dependent on __________
a) Minimum quantity of water available
b) Vegetation of the selected area
c) Maximum quantity of water available
d) Available head
Answer: a [Reason:] As the availability of water depends on natural phenomenon of rain, the maximum capacity of hydraulic generating plant is usually fixed on the basis of minimum quantity of water available at selected site.
9. What are used to store water during peak periods?
a) Storage drums
d) Storage Reservoirs
Answer: d [Reason:] The capacity of the hydraulic plant is done on the basis of minimum quantity available. Usually storage reservoirs are constructed for such plants in order to store the water during peak periods of runoff and supply the same during off peak periods of runoff.
10. The evaporation of water from the surfaces and its precipitation is known as ___________
c) Hydrological cycle
Answer: c [Reason:] It’s the science which deals with rainfall and runoff. The evaporation of the water from the surfaces of river and oceans and its precipitation on the earth is known as hydrological cycle. This happens in a particular amount of period.
1. What is range of temperature at Hydro thermal reservoirs?
Answer: a [Reason:] Hydrothermal resources are wet reservoirs at moderate depths containing steam and hot water under pressure at temperatures upto about 350oC. These systems are further subdivided depending upon whether steam or hot water is dominant product.
2. When do hydrothermal resources arise?
a) When the movement of tectonic plates occurs
b) When the area is prone to volcanic eruptions
c) When water has access to high temperature
d) When temperature on earth surface is very high
Answer: c [Reason:] Hydrothermal resources arise when water has access to high temperature rocks, this account for the description as HYDROTHERMAL. The heat is transported from the hot rocks by circulating movement.
3. How does the hot water or steam escape through earth surface?
a) Through fissures
b) Through Pot holes
c) From Wells
d) Through water bodies
Answer: a [Reason:] Hot water or steam often escapes through fissures in the rock, thus forming hot springs, geysers fumaroles etc. in order to utilize the hydrothermal energy, wells are drilled either to intercept a fissure or more commonly into the formation containing the water.
4. What is the range of depth of most Hydro thermal wells?
a) 600 – 2100m
b) 50 – 60 m
c) 8 – 10 km
d) 1200 – 5400m
Answer: a [Reason:] Most hydrothermal wells range in the depth from about 600 to 2100 m, although there are some shallower and deeper production wells. As already mentioned for practical purposes hydrothermal resources are further subdivided into vapor dominated and liquid dominated types.
5. How the steam after passing turbine is cooled down in the geo thermal energy plant?
a) Water cooled
b) Cooling towers
c) Air cooled (Blowers/ air vents)
d) Chemically cooled
Answer: b [Reason:] A direct system is used at the geysers in which the turbine exhaust steam is condensed by direct contact with cooling water. The resulting warm water is circulated through a mechanical draft cooling tower and returned to the condenser.
6. How much percent of Non-condensable gases are contained in steam?
a) 0.5 – 5%
b) 10 – 25%
c) 75 – 85%
Answer: a [Reason:] The steam contains 0.5 – 5% by weight of non-condensable gases which appear in the turbine exhaust. These gases consist mainly of carbon dioxide with small amounts of methane and ammonia, which are largely harmless in the quantities present.
7. The withdrawal of large amounts of steam from a hydrothermal reservoir may result in ____________
b) surface subsidence
c) light surface
d) loss of land fertility
Answer: b [Reason:] The withdrawal of large amounts of steam from a hydrothermal reservoir may result in surface subsidence. Such subsidences have sometimes occurred in oil fields and are dealt with injecting water into the ground.
8. What is the range of range of the water, which comes from degrees of salinity?
a) 300 – 8000 ppm
b) 4500 – 50,000 ppm
c) 70000 – 85000 ppm
d) 3000 – 280,000 ppm
Answer: d [Reason:] The water comes with various degrees of salinity, ranging from 3000 to 280,000 ppm of dissolved solids, and at various temperatures. There are, therefore, various systems for converting liquid dominated system into useful work that depend upon these variables.
9. Which among the following systems is used for water in high temperature range?
a) Vapor dominated systems
b) Flashed steam system
c) Liquid dominated total flow concept
d) Petro thermal systems
Answer: b [Reason:] Flashed steam system is used for water in the higher temperature range. Flash steam is low-pressure steam created when hot water is released from a high pressure to a lower pressure within a steam system.
10. Which geothermal systems are composed of hot dry rock (HDR) but no underground water?
a) Hybrid geothermal Fossil system
b) Flashed steam system
c) Liquid dominated total flow concept
d) Petro thermal systems
Answer: d [Reason:] Petro thermal systems are composed of hot dry rock (HDR) but no underground water. They are largest geothermal resource available. The rock occurring at moderate depths has very low permeability and needs to be increasing its heat transfer surface.
11. Which geothermal system utilizes relatively low temperature heat of geothermal sources?
a) Hybrid geothermal Fossil system
b) Flashed steam system
c) Liquid dominated total flow concept
d) Petro thermal systems
Answer: a [Reason:] The hybrid geothermal fossil fuel systems utilizes the relatively low temperature heat of geothermal sources in the low temperature end of a conventional cycle and the high temperature heat from fossil fuel combustion in the high temperature cycle with a natural source of heat for part of heat addition, thus reducing the consumption if the expensive and non renewable fossil fuels.
12. How many possible arrangements are there for Hybrid geothermal plants?
Answer: a [Reason:] There are two possible arrangements for hybrid plants. These are (1) geothermal preheat suitable for low temperature liquid dominated systems, and (2) fossil superheat, suitable for vapor dominated and high temperature liquid dominated systems.
1. Why does a large diesel engine plant require air?
a) To support combustion
b) To remove dust particles
c) To blow out fumes
d) To run the engine
Answer: a [Reason:] A large diesel engine plant requires about 0.076 m3/min to 0.11m3/min of air per KW of power developed inside the engine. Air contains lot of dust; hence it is necessary to remove the dust content in the atmospheric air.
2. What happens if atmospheric temperature is too low?
a) Engine misfires at low loads
b) Engine consumes more amount of fuel
c) Engine gets struck up
d) Exhaust produced comparatively more
Answer: a [Reason:] The air system contains an intake manifold located outside the building with filter to catch dirt which would otherwise cause excessive wear in the engine. If the atmospheric temperature is too low, engine misfires at low loads and hence it is necessary to install a heating element using exhaust gas.
3. What is used in engines to reduce the noise at the exhaust?
a) Noise dampers
d) Composite foam
Answer: c [Reason:] Engine sound during operation may be transmitted back through the air intake systems to the outside air. In such cases a silencer is provided between the engine and the intake. It is a light weight steel pipe.
4. In which type of dust filter used in engine is the air swept over or through the pool of oil??
a) Oil bath type
c) Soot blower
d) Bessel filter
Answer: a [Reason:] in oil bath type of filter the air is swept over or through a pool of oil. The dust particles become coated to the oil. The air is then passed through the filter, which retains the oil coated dust particles.
5. Which type of filter used in engine is made up of cloth, felt and glass wool?
b) Oil-bath type
c) Soot blower
d) Bessel filter
Answer: a [Reason:] Dry type of filter is made up of cloth, felt and glass wool etc. the filters catch dirt by causing it to cling to the surface of filter material. The capacity of such filters drops progressively when they are in use. The cleaning is done by amount of air used by the engines and dust concentrate in it.
6. What is muffling?
a) Reducing vibration
b) Increasing the flow of gas
c) Reducing noise
d) Filtering the exhaust air
Answer: c [Reason:] Muffling is the process of reducing the noise. The exhaust system must carry approximately 0.23 m3/min-0.30m3/min of gases per kilowatt developed, at the average exhaust temperature. Muffling of the exhaust noise is done by using silencers located outside building.
7. Exhaust pipe is designed carefully in order to carry toxic gases away from the user machine?
Answer: a [Reason:] An exhaust pipe must be carefully designed to carry toxic and noxious gases away from the users of the machine. It is done so because the gases produced may affect the human being in health wise as well as the environment.
8. Why is lubrication system important in the engine?
a) To improve fuel efficiency
b) To provide cooling
c) To reduce the disturbance
d) To help move the fuel easily
Answer: c [Reason:] Due to the presence of friction, wear and tear of the engine parts takes place reducing the engine life. The lubricant introduced forms a thin film between the rubbing surfaces and prevents metal to metal contact.
9. In which type of lubrication method are splash rods used?
a) Full pressure lubrication
b) Mechanical lubrication
c) Force feed lubrication
d) Spray lubrication
Answer: a [Reason:] In full pressure lubrication splash rods equipped. An oil pump supplies lubricating oil to many parts of the engine through duct system and to the crank shaft through drilled holes. The cylinder walls are lubricated by oil mist that is slung outward by the splash rod connected to flywheel from pool of oil.
10. Why is oil cleaning is necessary in the engine?
a) For continuous reliable operation
b) To cool down the oil
c) To reduce the viscosity of oil
d) To increase thickness of oil
Answer: a [Reason:] For continuous reliable operation attention should be given to oil cleaning. For this purpose filters with centrifuges or chemical action have been employed. Mechanical filters include cloth bags, wool, felt pads, paper discs and cartridge of porous material.
11. Rough cleaning of oil in engine is done through passing the oil through?
a) Paper discs
c) Felt pads
d) High speed centrifuges
Answer: d [Reason:] Rough cleaning of oil is done by passing oil through high speed centrifuges. Centrifuges can be done by periodic centrifuging of the entire lubricating oil or by continuous cleaning of a small fraction of it by splitting the oil from main flow and returning back to main stream.
12. Oil is cooled before passing it to the engine?
Answer: a [Reason:] Oil should be heated before passing it through the centrifuge and then it is cooled before supplying it to the engine. As heat is developed due to friction between the moving parts, the cooling is done by using water from the cooling tower.
1. Ash is widely used in the production of _______
b) Thermal wear
c) Food oxidants
Answer: d [Reason:] Ash is widely used in the production of cement. Fly ash is pozzolanic and develops self hardening characteristics. Concrete made of ash can yield improved workability and strength greater than all cement based concrete. The pozzolanic quality of ash lime mixture creates a healing of cracks in the pavement themselves.
2. Why is used for treating acidic soils?
a) To improve fertility of soil
b) For their better alkali values
c) To keep away insects
d) To loosen up the soil
Answer: b [Reason:] Due to their better alkali values, they are used for treating acidic soils. Its use for agricultural purposes is recently experimented in Japan and it is found that it supplies essential nutrients as sulfur, boron, calcium and zinc. It also adjusts pH to optimum levels for plant growth.
3. What is the India’s current total capacity of power plants installed?
Answer: a [Reason:] India’s current total installed capacity of power plants is 84000MW, out of which coal-fired thermal plants contribute 54000MW (65% of total). The World Bank estimated coal based power generation to increase by another 81000MW by 2010 which would have further increased fly ash load of 56 million tons per year.
4. How much percent of fly ash is, mixed with Portland cement?
a) 10 to 25%
b) 5 to 10%
c) 30 to 50%
Answer: a [Reason:] 10 to 25% dry fly ash can be used as during manufacture of cement or blended with finished Portland cement to produce Portland pozzolana cement whose strength is higher. The major drawback of this cement is its high cost and it requires more setting time.
5. Sintered light weight aggregates are produced by which method?
Answer: a [Reason:] Sintered light weight aggregates are produced by nodulisation of fly ash and sintering them at 1000oc to 1300oC. Unburnt fuel in the fly ash modules supports ignition. Sintered weight aggregate substitute’s chips in concrete reducing dead weight.
6. How much time period is fly ash stone powder cement bricks water cured?
a) A week
b) 2 weeks
c) 3 weeks
d) 1 month
Answer: d [Reason:] Fly ash stone powder cement bricks are manufactured by mixing weighted fly ash, cement and stone powder in a mixture and molded and pressed in brick making machine. The compacted bricks are water cure for a month. The compressive strength of these bricks varies from 70 to 110bar depending upon cement content.
7. How much amount of fly ash is made utilized by India?
a) 3 – 4%
b) 10 – 20%
c) 50 – 60%
d) 35 – 55%
Answer: a [Reason:] About 20% of coal ash in the coal is converted into bottom ash and 80% fly ash. India utilizes only 3 – 4% of fly ash generated as compared to 40% utilization in France and U.K. The government5t of India is imposing to achieve about 50% of fly ash in the upcoming years .
8. Which among the following when utilized gives good finishing on the both sides of the walls?
a) Cast-in-situ fly ash walls
b) Cellular light weight concrete
c) Sintered light weight aggregates
d) Fly ash cement putty
Answer: a [Reason:] Using high fly ash comprising of cement, lime fly ash and sand in appropriate proportions depending upon the quality of fly ash with pre-measured water cement ratio, cast-in-situ can be built. These can be cast to any thickness using steel shuttering. By using this system we can achieve 20% of economy, quicker construction, good finish on both sides of wall and more carpet area.
9. Which type of concrete is useful in high rise construction?
a) Cellular light weight concrete
b) Cast-in-situ fly ash
c) Fly ash stone powder bricks
d) Sintered light weight aggregates
Answer: a [Reason:] Cellular light weight cement can be manufactured by a process involving the mixing of fly ash, cement, coarse sand fine and a foaming agent. The slurry formed is poured in moulds and allowed to set. The blocks are then removed and cured by spraying water on the stack. The blocks are especially useful in high rise construction reducing the dead weight of the structure.