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Multiple choice question for engineering

Set 1

1. The automotive battery is also known as __________
a) lithium ion battery
b) lead-acid storage battery
c) zinc carbon battery
d) weston cell battery

View Answer

Answer: b [Reason:] The automotive battery, also known as Lead-acid storage battery is an electrochemical device that produced voltage and delivers current. In an automotive battery we can reserve the electrochemical action, thereby recharging the battery, which will then give many years of service.

2. What is present inside a battery?
a) Electrolyte
b) Fluids
c) Acid
d) Steam

View Answer

Answer: a [Reason:] The electrolyte inside the battery is a mixture of sulfuric acid and water. Sulfuric acid is very corrosive; if it gets on your skin it should be flushed with water. The automotive battery requires special handling. If it gets in your eyes it should be flushed with mild solution of baking soda and water.

3. What do batteries emit while charging?
a) Nitrogen
b) Oxygen
c) Hydrogen
d) Carbon

View Answer

Answer: c [Reason:] When charging, the battery will emit hydrogen gas; it is therefore extremely important to keep the flames and sparks away from battery. It is also advisable to wear goggles and gloves while servicing the battery.

4. The battery cannot be sealed because ____________
a) they emit noxious gases
b) they emit hydrogen
c) to be exposed to air
d) to have the ventilation

View Answer

Answer: c [Reason:] Because batteries emit hydrogen gas while charging, the battery case cannot be completely sealed. Years ago there was a vent cap for each cell and we had to replenish the cells when the electrolyte evaporated. Today’s batteries (maintenance free) have small vents on the side of the battery; the gases emitted have to go through baffles to escape.

5. What does CCA stand for in engine starting methods?
a) Circuit card assembly
b) Cold cranking amps
c) Chromated copper arsenate
d) Capital cost allowances

View Answer

Answer: b [Reason:] Today’s batteries are rated in term of cold cranking amps. This represents the current that the battery can produce for 30 seconds at 0oC before the battery voltage drops below 7.2 volts. An average battery today will have a CCA (Cold Cranking Amps) of 500.

6. Which of the following problem naturally occurs around the battery?
a) Corrosion
b) Scaling
c) Pore formation
d) Rust

View Answer

Answer: a [Reason:] Corrosion naturally occurs around the battery. Electrolyte condensation contains corrosive sulfuric acid, which destroys the metal of battery terminals, cable ends and battery hold down parts. To clean away the corrosion, use a mixture of baking soda and water.

7. How many key switch positions are there in general in ignition switch?
a) 2
b) 3
c) 4
d) 5

View Answer

Answer: d [Reason:] The ignition switch allows the driver to distribute electrical current to where it is needed. There are generally 5 key switch positions they are: 1) Lock 2) Off 3) Run 4) Start 5) Accessory.

8. In which switch position are all circuits open?
a) Lock
b) Run
c) Start
d) Accessory

View Answer

Answer: a [Reason:] In lock position all circuits are open and the steering wheel is in lock position. In some cars, the transmission lever cannot be moved in this position. If the steering wheel is applying pressure to the locking mechanism, the key might be hard to turn.

9. In which ignition switch position is the power supplied to ignition circuit?
a) Off switch position
b) Run switch position
c) Start switch position
d) Lock switch position

View Answer

Answer: c [Reason:] Power is supplied to the ignition circuit in start switch position. That is why the media stops playing in the start position. This position of the ignition switch is spring loaded so that the starter is not engaged while the engine is on. This position is used momentarily, just in order to activate the starter.

10. Neutral safety switch varies due to changes in ________
a) ignition
b) applying clutch
c) gear transmission
d) brakes

View Answer

Answer: c [Reason:] This switch opens (denies current to) the starter circuit when the transmission is in any gear but Neutral on automatic transmissions. This switch is normally connected to the transmission linkage or directly on the transmission. Most cars utilize this same switch to apply current to the backup lights when the transmission gear is put in reverse.

Set 2

1. Cusec is___________
a) A unit of flow equal to one cubic feet per sec
b) A unit of flow equal to one centimeter cube per sec
c) A unit of flow equal to one meter per sec
d) A unit of flow equal to one cubic foot per sec

View Answer

Answer: a [Reason:] Cusec is a unit of flow especially water which is equal to one cubic feet per sec. And there is also use of Cumec which is one cubic meter per second. One cubic feet per second is equal to 28.317 liters per second.

2. Find the power available if overall efficiency of plant is 80%, flow rate is 4.42cumecs and head 400m?
a) 6.52MW
b) 8.18MW
c) 11.255MW
d) 13.875MW

View Answer

Answer: d [Reason:] Power available: P = wQHno X 10-3 KW = 9810 X 4.42 X 400 X 0.8 X 10-6 MW P = 13.875MW.

3. What would be the pondage factor for if hydropower plant is used for 10 hours?
a) P.F = 2.4
b) P.F = 1.2
c) P.F = 20
d) P.F = 0.4166

View Answer

Answer: a [Reason:] Pondage factor = T1/T2 = (Total number of hours in one day)/(Total number of hours plant is running) P.F = 24/10 = 2.4.

4. Determine the capacity of hydro power plant to be used 10 hours peaking plant assuming daily flow in a river to be constant at 20m3/s. and overall efficiency is 80%?
a) 1.8835 MW
b) 5.5 MW
c) 3.25 MW
d) 1.0 MW

View Answer

Answer: a [Reason:] Capacity of plant: P = wQHno X 10-3 KW P = 9810 X 20 X 12 X 0.80 X 10-6 = 1.8835 MW.

5. Determine the flow rate of water, if the catchment area of hydroelectric power is 2500 km2, with an average rainfall of 160cm. the percolation and evaporation losses account for 19%.?
a) 9639.8M3/s
b) 42.8M3/s
c) 859.63M3/s
d) 2342M3/s

View Answer

Answer: a [Reason:] Amount of water available for power generation, Qa = A X H X (1-y) = 2500 X 106 X 160/100 (1-0.19) = 3.04 X 1011m3 Flow rate of water, Q = Qa/(365 X 24 X 60 X 60) = (3.04 X 10⩘-6)/(365 X 24 X 60 X 60) = 9639.8 M3/s.

6. Determine the power developed, IF given data is H= 150m, ng = 0.91, nt = 0.86 and Q is 9639.8?
a) 74MW
b) 75MW
c) 76MW
d) 78MW

View Answer

Answer: a [Reason:] Power developed = wQHno X 10-3 KW = 9810 X 9639.8 X 0.86 X 0.91 X 10-6 MW = 74 MW.

7. Determine the pondage factor if the plant is working at peak time of 16 hrs?
a) 1.5
b) 0.75
c) 2.5
d) 0.3

View Answer

Answer: a [Reason:] Pondage factor = T1/T2 = (Total number of hours in one day)/(Total number of hours plant is running) P.F = 24/16 = 1.5.

8. Find out the total flow volume in day sec meter for the average daily stream flow for 7 days?
Days Mean daily flow
1
2
3
4
5
6
7        100
300
200
120
50
30
20

a) 820 day sec meter
b) 95 day sec meter
c) 200 day sec meter
d) 524 day sec meter

View Answer

Answer: a [Reason:] Total flow volume for 7 days: = 24 X 3600 X (100+300+200+120+50+30+20) = 70848 X 103 m3 = 70.848 million m3 = 70848 X 103 / 86400 = 820 day sec meter.

9. Determine the pondage factor if the plant is working at time of 8 hrs?
a) 2.5
b) 3.8
c) 1
d) 3

View Answer

Answer: d [Reason:] Pondage factor = T1/T2 = (Total number of hours in one day)/(Total number of hours plant is running) P.F = 24/8 = 3.

10. What AEP stand for in hydrology?
a) Annual exceedance probability
b) Annual energy production
c) Annual exceedance period
d) Automatic engagement panel

View Answer

Answer: a [Reason:] Annual exceedance probability refers to the probability of a flood event occurring in any year. The probability is expressed as a percentage. The probability that a given rainfall total accumulated over a given duration will be exceeded in any one year.

11. What is the volume of rainfall in day sec-meters if 6.5cm rainfall occurs over an area of 2400 sq.km?
a) 1805.56 day sec meter
b) 1225 day sec meter
c) 895 day sec meter
d) 1555.22 day sec meter

View Answer

Answer: a [Reason:] Total rainfall energy-engineering-questions-answers-hydrographs-2-q11

12. A lake behind a dam has a capacity of 30000km2-m approximately. For how many days would this water supply be sufficient to a city of 106 populations if daily requirement per person is 500 liters?
a) 60,000 days
b) 950 days
c) 25000 days
d) 8000 days

View Answer

Answer: a [Reason:] Per day requirement: 500 X 103 liter = 500 X 103 m3 Available water in the dam = 30000 X 106 m3 No of days water supplied = 30000 X 106 / 500 X 103 = 60000 days

13. Determine the capacity of hydro power plant to be used 8 hours peaking plant assuming daily flow in a river to be constant at 65m3/s. and overall efficiency is 80% and head 12m?
a) 6.1214 MW
b) 5.5 MW
c) 31.25 MW
d) 22.0 MW

View Answer

Answer: a [Reason:] Capacity of plant: P = wQHno X 10-3 KW P = 9810 X 65 X 12 X 0.80 X 10-6 = 6.1214MW

14. A hydel plant is supplied from a reservoir of 5 X 106 m3 capacity at a head of 75m. Determine the number of electrical units produced (KWh) during the year if the load factor is 0.6 and overall efficiency of generation is 72%?
a) 441.45MWh
b) 300.22MWh
c) 235MWh
d) 182MWh

View Answer

Answer: a [Reason:] The power capacity of plant in KW is given as P = mgH/1000 X n{overall} = (5 X 106 X 1000 X 9.81 X 75 X 0.72) / (365 X 24 X 3600 X 1000) = 83.99Kw Energy produced in kWh = P X Load factor X (365 X 24) = 83.99 X 0.6 X 365 X 24 = 4441451.44kwh = 441.45 Mwh

15. The graph of the cumulative values of water quantity against time is known as __________
a) Flow curve
b) Power curve
c) Mass curve
d) Load curve

View Answer

Answer: c [Reason:] The graph of the cumulative values of water quantity against time is known as mass curve. A mass curve of the hydrograph which expresses the area under the hydrograph from one time to another.

Set 3

1. Power generation facilities have been affected by the concern for the _______
a) Environment
b) Availability of resources
c) Soaring costs
d) Humans

View Answer

Answer: a [Reason:] The design, location, construction and operation of electrical power generation facilities have been affected by the concern for the environment. Hence power engineer must have concern for the environment while producing enough power to meet public demand at low cost. Government has passed environmental legislation that limits amount of pollutants that can be discharged to the environment.

2. How many forms of sulfur exist in the atmosphere?
a) 1
b) 2
c) 3
d) 4

View Answer

Answer: 3 [Reason:] Sulfur in the atmosphere exists in three (3) forms: a. Sulfur dioxide, SO2 which comes from artificial causes. b. Hydrogen sulfide, H2S which comes from natural causes. c. Various sulfates, coming from sea spray and oxidation of SO2.

3. How much amount of sulfur dioxide is caused in the atmosphere?
a) SO2<25%
b) 50% <SO2>50%
c) 0%
d) SO2>50%

View Answer

Answer: a [Reason:] Although sulfur dioxide is caused by artificial causes, it is primary concern since it contributes >25% of all sulfur in the atmosphere. It is estimated that more than 90 million tons of sulfur dioxide are discharged into the atmosphere every year.

4. Acid rain is caused mainly by ___________
a) methane gas
b) sulphuric acid
c) sulfur dioxide
d) carbon dioxide

View Answer

Answer: c [Reason:] Acid rain and acid snow are caused by mainly by sulfur dioxide and also oxides of nitrogen and other sulfur oxides contribute fewer amounts to it. These gasses carried along wind currents combine with water molecules in the water vapor of the atmosphere, forming tiny drops. These drops when encountered by snow or rain producing clouds, results in acid rain.

5. Acid rain affects tree and plants.
a) True
b) False

View Answer

Answer: a [Reason:] Acid rain does affect trees and plants. It results in leaching of essential plants nutrients from the soil and reduces nitrogen fixation by microorganism. This makes soil less fertile. Also dissolve aluminum and cadmium out of soil minerals, allowing them to enter roots and kill trees.

6. By what type of reaction are Nitrogen oxides caused?
a) Endothermic reaction
b) Combustion reaction
c) Exothermic reaction
d) Synthesis reaction

View Answer

Answer: a [Reason:] Production of nitrogen oxides is an endothermic reaction and its concentration is temperature dependent. NOx emissions can be reduced by lowering the combustion temperature and by eliminating hotspots in the furnace.

7. Which among the following oxides are major contaminants in the atmosphere?
a) Nitrogen oxides
b) Oxides of carbon
c) Sulfur oxides
d) Particulate matter

View Answer

Answer: b [Reason:] Oxides of carbon such as CO, CH4 and CO2 are major contaminants in the atmosphere. Carbon monoxide is caused by natural causes partially, such as marsh gas, coal, vegetation and forest fires. This contribution is small compared to human generated causes. 90% of CO is produced by motor vehicles, where as power plants contribute less than 1%. The total amount of CO produced per year is 230 million tones.

8. Carbon dioxide (CO2) is largely contributed by __________
a) vehicles
b) power plants
c) humans
d) plants

View Answer

Answer: b [Reason:] Carbon dioxide is largely contributed by power plants. CO2 added to nature by natural causes viz., decay of organic matter contributes more than that by artificial causes. Also CO2 contaminants in atmosphere are not considered as pollutants as it is essential for plants.

9. By which process can CO2 be removed from the atmosphere?
a) Pyrolysis
b) Photosynthesis
c) Filtration
d) Magnetohydronomics

View Answer

Answer: b [Reason:] Carbon dioxide (CO2) can be removed by the process of photosynthesis. This process concerts back CO2 into oxygen and organic compounds in the presence of sunlight and water. However, more concentration of CO¬2 results in green house effects.

10. What causes green house effect?
a) Carbon dioxide
b) Carbon tetra oxide
c) Oxygen
d) Nitrogen

View Answer

Answer: a [Reason:] CO2 causes green house effect. The concentration of CO2 has increased to a level beyond the capacity of plant life and the oceans to completely remove it. 50% of CO2 added is retained in the atmosphere. And this retained CO2 causes green house effect.

11. In what form are the radiations coming from sun?
a) Long waves
b) Short waves
c) Transient waves
d) Longitudinal waves

View Answer

Answer: b [Reason:] The atmosphere, analogous to the glass panes of green house, transmits the radiation from the sun. The surface of sun is about 6000k and most of the radiation is in the form of short waves and visible portions of the spectrum, and only a portion of the radiation is absorbed or scattered back to the space by atmosphere.

12. What causes absorption of infrared radiations?
a) Large contents of CO2 and H2O
b) Sulfur oxides
c) Ozone
d) Earth gravity

View Answer

Answer: a [Reason:] The presence of CO2 and H2O in the atmosphere results in the absorption of large portions of infrared radiations from the surface and partial of those radiations back to earth. Thus atmosphere us not transparent completely to the reradiated energy and traps much of the energy from the sun.

13. What is the reason for melting of polar caps?
a) Increasing levels of sulfur
b) Depletion of ozone
c) Increasing levels of CO2
d) Longitudinal radiation

View Answer

Answer: c [Reason:] The growing levels of concentration of CO2 increase the surface temperature of earth. This may result in climatic changes with disastrous consequences, such as melting of polar ice caps and rising of sea levels.

14. What are the constituents of particulate matter?
a) Fluid gases
b) Smoke and dust
c) Flue gas
d) Poisonous gases

View Answer

Answer: b [Reason:] Particulate matter is composed of smoke, and other solids of variety of organic and materials. Both natural and human activities are responsible for the particulate matter in the atmosphere. These are the basic causes for the formation of smog and fog.

15. What is TDI stands for in the Thermal pollution field?
a) Turbocharger direct injection
b) Toluene Diisocyanate
c) Thermal energy discharge integration
d) Thermal discharge index

View Answer

Answer: d [Reason:] To compare power generating systems with respect to the amount of thermal energy discharged to the environment a term is introduced, known as thermal discharge index (TDI). The thermal discharge index of any power system is the number of thermal energy units discharged to the environment of each unit of electrical energy produced by plant.

Set 4

1. Where is the place at which the volatile matter and fine particles burnt in the spreader stoker?
a) Over the grate
b) In steam gauge
c) In the suspension
d) In the coal bed

View Answer

Answer: c [Reason:] The air supplied by the forced draught fan enters the furnace through the openings provided in the grate. A portion of this air is used to burn the fuel on the grate and remaining air is utilized to burn the volatile matter and fine particles in suspension.

2. From where is the over fire or secondary air is supplied through in the sprinkler stoker?
a) Air duct
b) Nozzle
c) Air damper
d) Tuyere’s

View Answer

Answer: b [Reason:] Over fire or secondary air is supplied through nozzle. The secondary air creates high turbulence and completes the combustion of volatile matter and fine particles of the coal. The unburnt coal and ash are deposited on the grate which should be removed periodically.

3. In which manner is the coal supplied from feeder to spreader in spreader stoker?
a) Feeding in alternate bulks
b) Feeding at regular intervals
c) Feeding in continuous stream
d) Feeding whenever necessary

View Answer

Answer: c [Reason:] The feeder is a slow speed rotating drum on which large numbers of small blades are mounted. It supplies coal to the spreaders in continuous stream. The speed of the feeder can be adjusted as per the load on plant. The feeders are operated with variable speed drive to control the combustion as per the requirement. The feeders may be reciprocating ram, endless belt or spiral worm.

4. Why are the blades of shaft in spreader stoker twisted?
a) For supporting combustion by supplying more amount of air
b) To draw in large amount of coal
c) For uniform distribution of coal
d) To restrict the supply of coal

View Answer

Answer: c [Reason:] Spreader consists of rapidly rotating shaft carrying blades. These blades are twisted to provide uniform distribution of the coal over the grate. The fast rotating blades hit the coal particles coming from the feeder and throw into the furnace. The distribution of coal over the grate depends on the rotating speed of the spreader and on the size of the coal.

5. How much capacity of heat is possible to produce by the travelling grate stoker?
a) 80 * 106 kJ/m2.hr
b) 40 * 106 kJ/m2.hr
c) 25 * 106 kJ/m2.hr
d) 65 * 106 kJ/m2.hr

View Answer

Answer: a [Reason:] The spreader stoker has wide applications with respect to the fuels used as well as to the boiler sizes. A wide variety and poor quality coal can be burnt efficiently with this type of stoker. This type of stoker can be used for boiler capacities of 80 tons to 150 tons of steam per hour. The heat release rate of 80 * 106 kJ/m2 hr is possible with travelling grate.

6. Which mechanism is used to supply coal in the single retort stoker?
a) Hopper
b) Chain bucket
c) Screw conveyor
d) Air blowers

View Answer

Answer: c [Reason:] The fuel is placed in the large hopper on the front of the furnace. Then it is further fed by reciprocating ram or screw conveyor into the bottom of the horizontal trough. The ash formed after burning of coal is collected at other end.

7. What are provided for the supply of air in single retort stoker?
a) Nozzles
b) Air ducts
c) Tuyere’s
d) Air blowers

View Answer

Answer: c [Reason:] The air is supplied through the tuyeres provided along the upper edge of the grate. The ash and clinkers are collected on the ash plate provided with dumping arrangement. The coal feeding capacity of a single retort stoker varies from 100 to 2000 kg per hour.

8. Which mechanism is used for the uniform distribution of the coal in multi retort stoker?
a) Reciprocating ram
b) Nozzle
c) Screw conveyor
d) Steam jet blowers

View Answer

Answer: a [Reason:] the multi retort stoker consists of a series of alternate retorts and tuyere boxes for supply of air. Each retort is fitted with a reciprocating ram for feeding and pusher plates for the uniform distribution of coal. The coal falling from the hopper is pushed forward during the inward stroke ram.

9. The low pressure air entering into the extension grate is supplied to ______________ in the multi retort stoker.
a) At incandescent zone
b) Thinner fuel bed
c) At inlet dampers
d) At extension grate

View Answer

Answer: b [Reason:] The primary air is supplied from the main wind box to the fuel bed situated below the stoker. The partly burnt coal moves on to the extension grate. The low pressure air entering into the extension grate, wind from main wind box is supplied to the thinner fuel bed on the extension grate. The quantity supplied can be regulated by air damper.

10. What is the reason for using forced draft in multi retort stoker?
a) Maintaining combustion for longer periods
b) Helps in blowing away the ash and clinkers
c) Causes rapid combustion
d) Maintains the intensity of fire

View Answer

Answer: c [Reason:] Forced draught causes rapid combustion. It is also necessary to introduce ‘over fire’ when high volatile coals are used to prevent the smoke formation. Combustion control is introduced into the stoker drive either by varying the ram stoke or by changing the rate of reciprocation.

Set 5

1. To how many types are flat plate collectors divided depending on type of heat transfer fluid?
a) 2
b) 3
c) 4
d) 5

View Answer

Answer: a [Reason:] Based on the type of heat transfer fluid, flat plate collectors are divided into two types, they are Liquid Heating Collectors and Air or gas heating collectors. And also happens that all other types of collectors come under these two types.

2. For what purpose are Gas heating collectors used?
a) To trap solar radiance
b) To act as a medium to help in conversion of sunlight to electrical energy
c) Employed as solar air heaters
d) They act as alternate panels in case of failure

View Answer

Answer: c [Reason:] Air or Gas heating collectors are employed as solar air heaters. Solar air heater is a type of system driving outdoor air through a sealed, sun heated collector mounted on an exterior wall or roof, returning the warmed air back to the living space.

3. Liquid heating collectors are mainly used for _________
a) heating water
b) generating electricity
c) cooking
d) trapping sunlight

View Answer

Answer: a [Reason:] Liquid heating collectors are mainly used for heating water. A liquid based solar collector is a solar collector that uses sunlight to heat a liquid that is circulating in a solar loop. The fluid in the solar loop may be water, an anti freeze mixture or thermal oil.

4. _______is a glazing which limits the radiation and convection heat losses.
a) Absorber plate
b) Selective surface
c) Insulation
d) Transparent cover

View Answer

Answer: d [Reason:] A transparent cover is glazing which limits the radiation and heat convection losses. It includes one or more sheets of glass or radiation transmitting plastic film or sheet. The glass itself is always a single pane adding to adding the second reduces the collector efficiency.

5. What are provided to minimize heat loss?
a) Absorber plate
b) Surface plate
c) Insulation
d) Casing

View Answer

Answer: c [Reason:] Insulation is provided at the back and sides to minimize heat losses. Fiber glass or styro-foam is used for this purpose. And also most modern collectors use standard insulators such as polyurethane or polyisocynurate.

6. Which part of flat plate collectors is coated in black?
a) Transparent cover
b) Absorber plate
c) Insulation
d) Fins

View Answer

Answer: b [Reason:] Absorber plate is usually metallic or coated in black surface which is used for absorbing radiation energy. The absorber plate’s coating directly affects how efficient the collector is. Coatings always have two rating figures: how much they absorb and how much they emit.

7. The frame which contains all the parts is called __________
a) box
b) plate
c) enclose
d) container

View Answer

Answer: d [Reason:] Container is used to enclose the other components to protect them from weather. These containers are made of extruded aluminum which can be quite heavy and thick for heavy duty collectors. There are some collectors which are enclosed by fiber glass too.

8. In which collector does air flow without any obstruction?
a) Porous absorber plate
b) Non-porous absorber plate
c) Over lapped glass absorber
d) Finned absorber

View Answer

Answer: b [Reason:] In a simple flat plate air collector, commonly known as non-porous absorbers, the air stream flow through the absorber plate without any obstruction. An analysis of black painted solar air collectors in conventional design in which the air flows below the absorber plate has been made.

9. In which absorber matrix material is arranged and the back absorber plate is eliminated?
a) Porous absorber plate
b) Non-porous absorber plate
c) Over lapped glass absorber
d) Finned absorber

View Answer

Answer: a [Reason:] In the porous bed air heater, the matrix material is arranged and the back absorber plate is eliminated. A single glazed porous bed collector with a reflecting honey comb, extending above the porous to just under the glass cover have theoretically examined.

10. Which type of absorber increases the heat transfer area over a simple flat plate absorber of the same capacity?
a) Porous absorber plate
b) Non-porous absorber plate
c) Over lapped glass absorber
d) Finned absorber

View Answer

Answer: d [Reason:] The finned plate absorber increases the heat transfer area over a simple flat absorber of same capacity. A good design of a finned absorber can increase the heat transfer rate. The temperature difference between the absorber plate and air is very low.

11. In which type of absorber plate is the overall flow direction is along the absorber glass plate?
a) Overlapped glass absorber
b) Finned absorber
c) Non-porous absorber plate
d) Porous absorber plate

View Answer

Answer: a [Reason:] In overlapped absorber plate, overall flow direction is along the absorber glass plate instead of being across the matrix. Plate and air stream temperature increase gradually along the collector length and across from top to bottom.

12. How is heat loss over come in liquid plate collectors?
a) By insulation
b) By casing
c) By the transparent cover
d) From provided tubes

View Answer

Answer: a [Reason:] Heat is transferred from the absorber plate to a point of use by the circulating fluid via water across the solar heated surface. The heat loss from the surface is prevented by placing thermal insulation of 5 to 10cm thickness behind the absorber plate.