Question 1
_______ lose more heat to the environment than evacuated-tube solar collectors.
A. Photovoltaics
B. Solar stills
C. Solar air conditioners
D. Flat-plate collectors
View Answer
Answer: Option D
Explanation:
Flat-plate collectors lose more heat to the environment than evacuated-tube solar collectors. Photovoltaics, solar stills and solar air conditioners are not solar collectors.
Answer: Option D
Explanation:
Flat-plate collectors lose more heat to the environment than evacuated-tube solar collectors. Photovoltaics, solar stills and solar air conditioners are not solar collectors.
Question 2
Adding antifreeze agents to water _________
A. increases its durability as coolant
B. decreases its durability as coolant
C. turns water into a coolant
D. prevents water from acting as a coolant
View Answer
Answer: Option A
Explanation:
Adding antifreeze agents to water increases its durability as coolant. This is because it depresses the freezing point of water and prevents it from becoming ice.
Answer: Option A
Explanation:
Adding antifreeze agents to water increases its durability as coolant. This is because it depresses the freezing point of water and prevents it from becoming ice.
Question 3
Aperture area of a solar collector is roughly equal to _______
A. Coolant area
B. Generator area
C. Absorber area
D. System area
View Answer
Answer: Option C
Explanation:
In a solar collector, the aperture area is approximately equal to absorber area. This enables absorption of (almost) all the sunlight that is incident on the aperture area.
Answer: Option C
Explanation:
In a solar collector, the aperture area is approximately equal to absorber area. This enables absorption of (almost) all the sunlight that is incident on the aperture area.
Question 4
Bowl collectors operate similarly to _______
A. parabolic dish
B. flat plate collector
C. evacuated-tube collector
D. evacuated flat tube collector
View Answer
Answer: Option A
Explanation:
Bowl collectors operate similarly to a parabolic dish. However, they have a fixed receiver unlike a parabolic dish. This reduces efficiency but is much cheaper to build and operate.
Answer: Option A
Explanation:
Bowl collectors operate similarly to a parabolic dish. However, they have a fixed receiver unlike a parabolic dish. This reduces efficiency but is much cheaper to build and operate.
Question 5
Bowl collectors use a fixed curved receiver.
A. TRUE
B. FALSE
View Answer
Answer: Option A
Explanation:
Bowl collectors use a fixed curved receiver. They have a fixed spherical mirror with a tracking receiver.
Answer: Option A
Explanation:
Bowl collectors use a fixed curved receiver. They have a fixed spherical mirror with a tracking receiver.
Question 6
Evacuated flat-plate solar collectors are a type of _______
A. concentrating collectors
B. photovoltaic technology
C. non-concentrating collectors
D. solar stills
View Answer
Answer: Option C
Explanation:
Evacuated flat-plate solar collectors are a type of non-concentrating collectors. Solar stills and photovoltaic technology are not solar collectors.
Answer: Option C
Explanation:
Evacuated flat-plate solar collectors are a type of non-concentrating collectors. Solar stills and photovoltaic technology are not solar collectors.
Question 7
Evacuated flat-plate solar collectors use _______ pumps.
A. Heat pump
B. Flash getter pump
C. Non-evaporable getter
D. Internal combustion
View Answer
Answer: Option C
Explanation:
Evacuated flat-plate solar collectors use non-evaporable getter (NEG) pumps to keep the internal pressure stable throughout the operation. This pump enables some regeneration in-situ by exposure to sunlight.
Answer: Option C
Explanation:
Evacuated flat-plate solar collectors use non-evaporable getter (NEG) pumps to keep the internal pressure stable throughout the operation. This pump enables some regeneration in-situ by exposure to sunlight.
Question 8
Evacuated tube solar collectors use a glass tube to surround absorber with high vacuum.
A. TRUE
B. FALSE
View Answer
Answer: Option A
Explanation:
Evacuated tube solar collectors use a glass tube to surround absorber with high vacuum. This is used to effectively resist atmospheric pressure and reduce conductive and convective losses.
Answer: Option A
Explanation:
Evacuated tube solar collectors use a glass tube to surround absorber with high vacuum. This is used to effectively resist atmospheric pressure and reduce conductive and convective losses.
Question 9
For better efficiency, solar collectors do not coat their transparent cover with an anti-reflective coating.
A. TRUE
B. FALSE
View Answer
Answer: Option B
Explanation:
For better efficiency, solar collectors coat their transparent cover with an anti-reflective coating. The anti-reflective coating reduces the amount of reflection dramatically. Thus, the amount of sunlight collected is increased.
Answer: Option B
Explanation:
For better efficiency, solar collectors coat their transparent cover with an anti-reflective coating. The anti-reflective coating reduces the amount of reflection dramatically. Thus, the amount of sunlight collected is increased.
Question 10
Polymer flat plate collectors can use plain water.
A. TRUE
B. FALSE
View Answer
Answer: Option A
Explanation:
Polymer flat plate collectors can use plain water. This is because they are freeze-tolerant and do not require antifreeze agents to prevent water from solidifying.
Answer: Option A
Explanation:
Polymer flat plate collectors can use plain water. This is because they are freeze-tolerant and do not require antifreeze agents to prevent water from solidifying.
Question 11
What advantage does polymer collector have over metal collector?
A. Better sales as they are produced in Europe
B. Poor sales as they are produced in Europe
C. They cannot be used in cold climate
D. They can be used in cold climate
View Answer
Answer: Option D
Explanation:
The primary advantage of a polymer collector over a metal collector is that they can be used in cold regions with low temperatures. This is because they are freeze-tolerant. Whether they are manufactured in Europe or not does is neither an advantage nor a disadvantage.
Answer: Option D
Explanation:
The primary advantage of a polymer collector over a metal collector is that they can be used in cold regions with low temperatures. This is because they are freeze-tolerant. Whether they are manufactured in Europe or not does is neither an advantage nor a disadvantage.
Question 12
What is a heat pipe?
A. A heat-transfer device
B. A pipe made of heat
C. A pipe that consists of heat
D. A heat pumping device
View Answer
Answer: Option A
Explanation:
A heat pipe is a heat-transfer device. It combines the principles of thermal conductivity and phase transition to effectively transfer heat between two solid interfaces.
Answer: Option A
Explanation:
A heat pipe is a heat-transfer device. It combines the principles of thermal conductivity and phase transition to effectively transfer heat between two solid interfaces.
Question 13
What is a solar collector?
A. A system to collect heat by absorbing sunlight
B. A system to collect rainwater using sunlight
C. A system to collect electricity by using sunlight
D. A device to reflect sunlight back
View Answer
Answer: Option A
Explanation:
A solar collector is a system to collect heat by absorbing sunlight and use it for various applications. It is neither a system to collect rainwater nor electricity. However, it could be used to perform such processes.
Answer: Option A
Explanation:
A solar collector is a system to collect heat by absorbing sunlight and use it for various applications. It is neither a system to collect rainwater nor electricity. However, it could be used to perform such processes.
Question 14
What is aperture area in a solar collector?
A. Area of the system
B. Area in the receiver that receives the solar radiation
C. Area occupied by the system after installation
D. Cross-sectional area of the receiver
View Answer
Answer: Option B
Explanation:
Aperture area of a receiver is that area which receives the solar radiation. It need not be same as the entire size of the receiver. It is not same as the area occupied by the system after installation.
Answer: Option B
Explanation:
Aperture area of a receiver is that area which receives the solar radiation. It need not be same as the entire size of the receiver. It is not same as the area occupied by the system after installation.
Question 15
What is the metal sheet absorber surrounded with in an evacuated flat plate collector?
A. Low volume inside flat envelope
B. Low vacuum inside curved envelope
C. High vacuum inside flat envelope
D. Low vacuum inside thick curved envelope
View Answer
Answer: Option C
Explanation:
In an evacuated flat-plate solar collector, the metal sheet absorber is surrounded with a high vacuum. This is then placed inside a flat envelope made of glass and metal.
Answer: Option C
Explanation:
In an evacuated flat-plate solar collector, the metal sheet absorber is surrounded with a high vacuum. This is then placed inside a flat envelope made of glass and metal.
Question 16
Which of the following are combined to form an evacuated flat plate solar collector?
A. Flat plate solar collectors and evacuated-tube solar collectors
B. Flat plate solar collectors and bowl collectors
C. Bowl collectors and evacuated-tube solar collectors
D. Polymer collectors and bowl collectors
View Answer
Answer: Option A
Explanation:
Evacuated flat plate collectors combine the technologies of both, flat plate solar collectors and evacuated-tube solar collectors. There are not a combination of bowl and polymer type collectors.
Answer: Option A
Explanation:
Evacuated flat plate collectors combine the technologies of both, flat plate solar collectors and evacuated-tube solar collectors. There are not a combination of bowl and polymer type collectors.
Question 17
Which of the following are used as absorbers in evacuated-tube solar collectors?
A. Carbon tubes
B. Wooden or metallic tubes
C. Plastic or glass tubes
D. Metallic or glass tubes
View Answer
Answer: Option D
Explanation:
Metallic or glass tubes are used as absorbers in evacuated-tube solar collectors. Wood and plastic are thermal insulators and hence, cannot be used to create passageways for the heat carrying circulating fluid.
Answer: Option D
Explanation:
Metallic or glass tubes are used as absorbers in evacuated-tube solar collectors. Wood and plastic are thermal insulators and hence, cannot be used to create passageways for the heat carrying circulating fluid.
Question 18
Which of the following is a circulating fluid in evacuated flat-plate solar collectors?
A. Water
B. Steam
C. Nitrogen
D. Hydrogen
View Answer
Answer: Option B
Explanation:
Evacuated flat-plate solar collectors are a more recent technology. It uses steam as its circulating fluid. Nitrogen and hydrogen are not used as circulating fluid. Water is mainly used in flat-plat collectors.
Answer: Option B
Explanation:
Evacuated flat-plate solar collectors are a more recent technology. It uses steam as its circulating fluid. Nitrogen and hydrogen are not used as circulating fluid. Water is mainly used in flat-plat collectors.
Question 19
Which of the following is a problem with evacuated tubes?
A. Underheating
B. Overheating
C. Poor absorption of sunlight
D. Poor reception of sunlight
View Answer
Answer: Option B
Explanation:
Overheating is a common problem with evacuated-tube solar collector. This is because of the high temperatures of the circulating fluid caused by collection of large amount of sunlight.
Answer: Option B
Explanation:
Overheating is a common problem with evacuated-tube solar collector. This is because of the high temperatures of the circulating fluid caused by collection of large amount of sunlight.
Question 20
Which of the following is generally used as circulating fluid in freezing climates?
A. Liquid carbon dioxide
B. Water
C. A mixture of propylene glycol and water
D. Liquid nitrogen
View Answer
Answer: Option C
Explanation:
In freezing climates, antifreeze solution like a mixture of water with propylene glycol or ethylene glycol or glycerol is used as coolants. Liquid carbon dioxide, water and liquid nitrogen are not used as coolants in freezing climates.
Answer: Option C
Explanation:
In freezing climates, antifreeze solution like a mixture of water with propylene glycol or ethylene glycol or glycerol is used as coolants. Liquid carbon dioxide, water and liquid nitrogen are not used as coolants in freezing climates.
Question 21
Which of the following is generally used as circulating fluid in tropical and sub-tropical climates?
A. A mixture of ethylene glycol and water
B. Water
C. A mixture of propylene glycol and water
D. Glycerol
View Answer
Answer: Option B
Explanation:
Water is used as circulating fluid in tropical and sub-tropical climates. This is because it has good properties as a coolant. A mixture of water with ethylene glycol or glycerol or propylene glycol is not used as coolant in tropical and sub-tropical climates.
Answer: Option B
Explanation:
Water is used as circulating fluid in tropical and sub-tropical climates. This is because it has good properties as a coolant. A mixture of water with ethylene glycol or glycerol or propylene glycol is not used as coolant in tropical and sub-tropical climates.
Question 22
Which of the following is used to make a glass-glass evacuated tubes?
A. Borosilicate glass
B. Carbon
C. Wood
D. Plastic coating
View Answer
Answer: Option A
Explanation:
As the name suggests, glass-glass evacuated tubes is a type of evacuated-tube solar collector. It is made up of two borosilicate glass tubes fused together at one or both ends.
Answer: Option A
Explanation:
As the name suggests, glass-glass evacuated tubes is a type of evacuated-tube solar collector. It is made up of two borosilicate glass tubes fused together at one or both ends.
Question 23
Which of the following organisations developed first high vacuum insulation?
A. NASA
B. IIT
C. Stanford
D. CERN
View Answer
Answer: Option D
Explanation:
CERN developed the first collector making use of high vacuum insulation. However, the first company to commercialise the technology was TVP SOLAR SA of Switzerland.
Answer: Option D
Explanation:
CERN developed the first collector making use of high vacuum insulation. However, the first company to commercialise the technology was TVP SOLAR SA of Switzerland.
Question 24
Which of the following pumps is used in an evacuated-tube solar collector?
A. Non-evaporable getter
B. Flash getter pump
C. Heat pump
D. Water pump
View Answer
Answer: Option B
Explanation:
Evacuated flat-plate solar collectors use a barium flash getter pump. This pump is used to keep the internal pressure stable throughout the operation. They do not use non-evaporable getter pumps.
Answer: Option B
Explanation:
Evacuated flat-plate solar collectors use a barium flash getter pump. This pump is used to keep the internal pressure stable throughout the operation. They do not use non-evaporable getter pumps.
Question 25
Why are antifreeze solutions (antifreeze agents with water) used as coolants in freezing climates?
A. To increase boiling point of water
B. To decrease boiling point of water
C. To increase freezing point of water
D. To decrease freezing point water
View Answer
Answer: Option D
Explanation:
Antifreeze solution is used as coolants in freezing climates. This is because they decrease the freezing point of water thereby preventing it from solidifying into ice.
Answer: Option D
Explanation:
Antifreeze solution is used as coolants in freezing climates. This is because they decrease the freezing point of water thereby preventing it from solidifying into ice.
Question 26
Why does an evacuated flat plate collector require a glass-metal seal?
A. To join the glass plate to the rest of metal envelope
B. To join the glass plate to a part of metal envelope
C. To disconnect the glass plate to the rest of plastic envelope
D. To disconnect the glass plate to the rest of metal envelope
View Answer
Answer: Option A
Explanation:
An evacuated flat plate collector requires a glass-metal seal. This is to join the glass plate to the rest of metal envelope. It also requires an internal structure to support such a plate against atmospheric pressure.
Answer: Option A
Explanation:
An evacuated flat plate collector requires a glass-metal seal. This is to join the glass plate to the rest of metal envelope. It also requires an internal structure to support such a plate against atmospheric pressure.
Question 27
Why does flat plate collector perceived to have higher efficiency than evacuated tube solar collector in terms of area?
A. Because flat plate collector has a large installation area
B. Because evacuated tube collector is compact
C. Because of the vacuum gap in evacuated tube collectors
D. Because of the vacuum gap in flat plate collectors
View Answer
Answer: Option C
Explanation:
In terms of area, flat plate solar collectors are generally perceived to have a higher efficiency than evacuated-tube solar collectors. This is because of the vacuum gap in evacuated tube collectors which increases their net occupied area.
Answer: Option C
Explanation:
In terms of area, flat plate solar collectors are generally perceived to have a higher efficiency than evacuated-tube solar collectors. This is because of the vacuum gap in evacuated tube collectors which increases their net occupied area.
Question 28
Why is a transparent cover used in a flat plate collector?
A. To maximize transmission of the incident sunlight into the box
B. To minimize transmission of the incident sunlight into the box
C. To entirely reflect the incident sunlight back
D. To ensure partial transmission of the incident sunlight into the box
View Answer
Answer: Option A
Explanation:
A transparent cover is used in a flat plate collector. This is because it maximizes the transmission of the incident sunlight into the box thereby collecting maximum sunlight for thermal energy.
Answer: Option A
Explanation:
A transparent cover is used in a flat plate collector. This is because it maximizes the transmission of the incident sunlight into the box thereby collecting maximum sunlight for thermal energy.