Category: Renewable Energy Objective Questions

Geothermal Energy online test on “Types of Geothermal Resources – 2”.

1. Which of the following is a type of high temperature geothermal resource?
a) Dry steam
b) Dry water
c) Wet steam
d) Water
Answer: a
Clarification: High temperature hydrothermal resource is used to produce electricity. The two main types of high temperature hydrothermal resources are dry steam and hot water.

2. Dry steam is _________ dominated.
a) liquid
b) vapour
c) solid
d) plasma
Answer: b
Clarification: Dry steam is a type of high temperature hydrothermal resource. It is vapour dominated. It is mainly used to generate electricity.

3. Hot water is _________ dominated.
a) vapour
b) nitrogen
c) liquid
d) Bose-Einstein condensate
Answer: c
Clarification: Hot water is liquid dominated high temperature hydrothermal resource. Like dry steam, it is used to generate electricity. Unlike low temperature resources, it cannot be used directly.

4. Which of the following is also called as a flash steam plant?
a) Low temperature hydrothermal resource
b) Dry steam
c) Hydrogen
d) Hot water
Answer: d
Clarification: Hot water is a high temperature hydrothermal resource. It is also called as flash steam plant because the hot water is first converted to steam. This steam is used to drive the turbines to generate electricity.

5. What is hot dry rock geothermal resource made of?
a) Granite
b) Soil
c) Solid carbon dioxide
d) Liquid nitrogen
Answer: a
Clarification: Hot dry rock is made up of granite. It is a unique geothermal resource that lacks stored fluid and has extremely low permeability. Fracture creation is required for commercial applications.

6. Which of the following fracture creation techniques is/are used in hot dry rock geothermal resource?
a) Condensation and hydrofracking
b) Hydrofracking and hydroshearing
c) Hydroshearing and distillation
d) Hydrofracking and combustion
Answer: b
Clarification: Hydrofracking and hydroshearing are the two commonly used fracture creation techniques for practical applications hot dry rock. Condensation, distillation and combustion are not fracture creation techniques.

7. What is the difference between enhanced geothermal system and hot dry rock?
a) Lack of fluid permeability
b) Fluid permeability
c) Presence of fluid
d) Presence of rocks
Answer: c
Clarification: The main difference between enhanced geothermal system and hot dry rock is the presence of fluid. Enhanced geothermal system contains hot fluid but hot dry rock does not or contains negligible amounts.

8. What is the similarity between enhanced geothermal system and hot dry rock?
a) Magma
b) Presence of steam
c) Presence of fluid
d) Lack of fluid permeability
Answer: d
Clarification: The main similarity between the two is that both lack fluid permeability. Magma is not the right option because it is present irrespective of the resource. In fact, it heats the resource. Both the resources lack steam.

9. Enhanced geothermal resource is man-made.
a) True
b) False
Answer: a
Clarification: Enhanced geothermal resource is a man-made reservoir. It is created where there is hot rock but insufficient or little permeability of the fluid.

10. Deep hydrothermal systems are found at a depth of ______
a) 1km
b) 2.5 – 5km
c) 10km
d) 1 – 2km
Answer: b
Clarification: Deep hydrothermal systems are found at a depth of 2.5 – 5km. The surrounding regions do not have elevated geothermal temperature gradients and the temperature range is between 120 – 140 degree Celsius.

11. What are deep hydrothermal systems?
a) Hot dry rock
b) Magma
c) Permeable and fluid saturated region
d) Impermeable and fluid saturated region
Answer: c
Clarification: Deep hydrothermal systems consists of permeable and saturated fluid in the surrounding region at a depth of 2.5 – 5km below the earth. The region is surrounded by magma and can be used to generate electricity.

12. Which of the following is responsible for the volcanic geothermal heat?
a) Water
b) Hot dry rock
c) Carbon dioxide
d) Supercritical water
Answer: d
Clarification: Supercritical water is responsible for the volcanic geothermal heat. The energy obtained from this supercritical water is much higher than conventional geothermal steam. Carbon dioxide does not contribute to any geothermal resource. Hot dry rock is a geothermal resource found beneath earth’s surface and not near volcanoes.

13. Supercritical water is a liquid.
a) False
b) True
Answer: a
Clarification: Supercritical water is a unique state of water where it neither behaves as a true liquid nor as a true gas. It is capable of generating upto 10 times more power than conventional geothermal sources.

14. Where is geothermal energy from volcanoes being harvested?
a) United States
b) Iceland
c) Iran
d) Greenland
Answer: b
Clarification: Iceland is a nation built on about 130 volcanoes. It rests above a divergent plate boundary which brings continuous supply of hot and fresh magma from the mantle. Iceland Deep Drilling Project (IDDP) is the most famous amongst all the other projects.

15. Geothermal power plants are very good sources for baseload power.
Note – Baseload power is power that electric utility companies must deliver all day long.
a) True
b) False
Answer: a
Clarification: Geothermal power plants are very good sources for baseload power. Except for the high initial costs, they produce electricity very cheaply – 4.5 to 7 cents per KWh. In fact, baseload geothermal plants sell electricity all the time even when during high demand.

Education & Learning Series – Geothermal Energy.

Geothermal Energy for online tests,
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Renewable Energy Multiple Choice Questions on “Advantages and Disadvantages of Conventional Energy Sources”.

1. Conventional Energy Sources are cheaper than Non-Conventional Sources.
a) True
b) False
Answer: a
Clarification: At present Conventional Energy Sources are cheaper than Non-Conventional sources. Since the Non-Conventional sources are relatively new in terms of usage, the technology for harnessing energy from these sources is not well developed. The cost/kWh of electrical energy obtained from different conventional sources are as follows:
Coal- 1.65 ₹/kWh
Diesel- 3.00 ₹/kWh
Hydropower- 1.00 ₹/kWh
Nuclear – 1.20 ₹/kWh
which is less than the cost/kWh of the non-conventional sources.

2. Which of the following pollutants are emitted by the burning of fossil fuel?
a) Oxides of Carbon, Nitrogen, and Sulphur
b) Oxides of Carbon, Uranium, and Radium
c) Calcium Halides and Oxides of Nitrogen
d) Noble Gases
Answer: a
Clarification: Fossil fuels generate Oxides of Carbon like CO and CO₂, Oxides of Nitrogen like NO and NO₂, and Oxides of Sulphur like SO₂ and SO₃. Apart from that particulate matter and heat is also generated by fossil fuels.

3. _____ is a petrochemical and is used as raw material for chemical, pharmaceutical, and paint industry.
a) Plutonium
b) Uranium
c) Coal
d) Protactinium
Answer: c
Clarification: Coal is a valuable petrochemical and is used as a raw material in many industries i.e. Chemical, Pharmaceutical, and Paint industry. From a long-term perspective, it is essential to conserve coal for future needs as a raw material.

4. Which of the following statements is not true about radioactive waste?
a) It has radioactivity quotient of dangerous levels.
b) The disposed radioactive waste is to be guarded for a long period
c) It has low radioactivity quotient
d) Its radioactivity decreases with time
Answer: c
Clarification: The waste generated in Nuclear power plants has radioactivity quotients of dangerous levels, it remains above the safe limit for a long time, and this is a health hazard. The radioactive waste is to be guarded for a long time until its radioactivity level comes to a safe limit.

5. Which of the following is not a disadvantage of Hydro Power?
a) A large land area submerges into the water leading to deforestation
b) It causes dislocation of a large population and rehabilitation
c) It causes ecological disturbances like earthquake
d) It causes calamities like landslides
Answer: d
Clarification: To clear the land area deforestation is done and sometimes it is needed to dislocate the local people to clear areas for dams. Large dams have abilities to trigger earthquakes. The earliest Dam Induced Earthquake was observed in Algeria in 1932.

6. Sweden banned _______ in 1984.
a) pesticides
b) new nuclear power plants
c) biogas plants
d) mining of fossil fuels
Answer: b
Clarification: Due to various hazards associated with Nuclear Energy Sweden banned New Nuclear power plants since 1984 and has plans to dismantle the existing plants.

7. Which Oxides of Nitrogen are generated by burning of fossil fuel?
a) NO and NO₂
b) NO₂, NO₃, and N₂O₅
c) N₂O₅ and N₂O₃
d) NO₃ and N₂O₅
Answer: a
Clarification: Burning of fossil fuels cause emission of Nitrogen Oxides. NO and NO₂ are the major Nitrogen oxides produced by the combustion of fossil fuel. These oxides cause smog and contribute to acid rain.

8. 3 percentage of the total greenhouse gas emissions are due to Hydropower plants.
a) True
b) False
Answer: b
Clarification: Hydropower plant doesn’t require burning of fuel so no pollutants are emitted. It converts the potential energy of falling water to kinetic energy which is converted to electricity.

9. Which Uranium isotope is used in nuclear power plants?
a) U-235
b) U-234
c) U-215
d) U-218
Answer: a
Clarification: U-235 and U-238 are naturally occurring isotopes of Uranium. U-235 is ideal for Nuclear energy because it splits easily and gives off a lot of energy. U-238, on the other hand, has a longer half life and takes more time to decay. U-215 and U-218 are artificially produced isotopes of Uranium.

10. Based on the following statements, choose the correct option.
Statement I: The technology for harnessing fossil fuels is well developed.
Statement II: Fossil fuels are a cheap source of energy.
a) Statement -I is true, Statement -II is true and Statement -II is the correct explanation of Statement -I
b) Statement-I is true, Statement -II is true and Statement -II is not the correct explanation of Statement-II
c) Statement -I is true and Statement -II is false
d) Statement -I is false and Statement -II is true
Answer: b
Clarification: The technology for harnessing fossil fuels is well developed because fossil fuels are being used for many decades. At present Fossil Fuels are Cheaper than non-conventional energy sources. Hence both the statements are correct but statement-II doesn’t explain statement-I.

Solar Energy Multiple Choice Questions on “Solar Radiation Geometry – 1”.

1. What is angle subtended by sun on earth in degrees?
a) About 0.5 degrees
b) About 1 degree
c) About 35 degrees
d) About 5 degrees
Answer: a
Clarification: Sun subtends an angle of 32 minutes at earth’s surface. When converted to degrees, it comes out to be 0.53 degrees.

2. Why is angle subtended by sun on earth’s surface so small?
a) Because sun is smaller than earth
b) Because of the large distance between earth and sun
c) Because of the small distance between earth and sun
d) Because sun is about the same size as that of earth
Answer: b
Clarification: The angle subtended by sun on earth’s surface is about 0.53 degrees. It is so small because of the large distance between the earth and sun.

3. When revolving around the sun, the earth moves in an elliptical cycle _______
a) on the sun’s plane
b) above the sun’s plane
c) above and below the sun’s plane
d) below the sun’s plane
Answer: c
Clarification: When revolving around the sun, the earth moves in an elliptical path. The earth passes above and below the sun’s plane to complete an elliptical cycle.

4. Which month is the earth closes to the sun?
a) February
b) March
c) December
d) January
Answer: d
Clarification: Earth is closest to the sun in January. Specifically, earth is closes on January 3^rd. The distance between earth and sun is approximately 147.3 million km.

5. What is aphelion?
a) The point where earth is farthest from the sun
b) The point where earth is nearest from the sun
c) The point where earth is on the perpendicular bisector of sun’s plane
d) The point when earth subtends an angle of 30 degrees with sun’s plane
Answer: a
Clarification: Aphelion is the point where earth is farthest from the sun. The point where earth is nearest to the sun is called perihelion.

6. Which month is the earth farthest from the sun?
a) June
b) July
c) August
d) January
Answer: b
Clarification: Earth is farthest from the sun in July. Specifically, it is farthest on 4^th July. The distance between earth and sun is approximately 152.1 million km.

7. What is solstice?
a) The point where earth is farthest from the sun
b) The point where earth is nearest from the sun
c) When sun’s zenith is at its furthest point from celestial equator
d) When sun’s zenith is at its closest point from celestial equator
Answer: c
Clarification: Solstice occur when sun’s zenith is at its furthest point from celestial equator. It could either be the northerly zenith or the southerly zenith.

8. What is sun declination angle?
a) Angle between sun and earth
b) Angle between ray of the sun touching earth’s surface and the equatorial plane
c) Angle between an observer on earth and the celestial equatorial plane
d) Angle between ray of the sun when extended to the earth’s center and the equatorial plane
Answer: d
Clarification: Sun declination angle is the angle between ray of the sun when extended to the earth’s center and the equatorial plane. It is positively oriented when sun’s rays reach the center through northern hemisphere and negative when the sun’s rays reach through southern hemisphere.

9. What is sun’s declination angle during summer solstice?
a) 23.5 degrees
b) 0.53 degrees
c) 32 minutes
d) -23.5 degrees
Answer: a
Clarification: Sun’s declination angle during summer solstice is 23.5 degrees. Thus, the sun shines down on the Tropic of Cancer in the northern hemisphere.

10. What is sun’s declination angle during winter solstice?
a) 25 degrees
b) -23.5 degrees
c) 37 degrees
d) 23.5 degrees
Answer: b
Clarification: Sun’s declination angle during summer solstice is -23.5 degrees. Thus, the sun shines down on the Tropic of Capricorn in the southern hemisphere and remains below the horizon everywhere within Arctic Circle.

11. What is an equinox?
a) When earth is farthest from the sun
b) When earth is nearest to the sun
c) When earth’s center lies in the plane of sun
d) When earth’s center does not lie in the plane of sun
Answer: c
Clarification: An equinox occurs when the earth’s center lies on the plane of sun. There are two such occasions throughout the year. Perihelion is the point where earth is nearest to the sun. Aphelion is the point where earth is farthest from the sun.

12. Why does earth receive 12 hours of sunshine during equinox?
a) Because earth’s center lies on the plane of the sun
b) Because earth’s center does not lie on the plane of the sun
c) Because earth is nearest to the sun
d) Because earth’s axis is perpendicular to the plane of the sun
Answer: d
Clarification: During equinox, earth receives 12 hours of sunshine. This is mainly because earth’s north-south axis of rotation is perpendicular to the plane of the sun.

13. What is the sun’s declination angle during equinox?
a) 0 degrees
b) 1 degree
c) 13 degrees
d) 23.5 degrees
Answer: a
Clarification: Sun’s declination angle has a measure of 0 degrees on the days of equinox. The declination angle is 23.5 degrees during summer solstice and -23.5 degrees during winter solstice.

14. The equinoxes are vernal equinox and autumnal equinox respectively.
a) True
b) False
Answer: a
Clarification: The equinoxes are vernal equinox and autumnal equinox respectively. The sun has a 0 degree declination angle on these two days of the year.

15. On summer solstice, the sun is above the horizon in northern hemisphere.
a) True
b) False
Answer: a
Clarification: On summer solstice, the sun is above the horizon for longest period of time in northern hemisphere. Hence, it is the longest fay for daylight.

Solar Energy,
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Solar Energy Multiple Choice Questions on “Solar Distillation or Desalination of Water”.

1. What is solar distillation?
a) Use solar energy to evaporate water and collect its condensate within the same closed system
b) Use solar energy to evaporate water and collect it within the same closed system
c) Use solar energy to collect the condensate of water within the same closed system
d) Use solar energy to evaporate water and collect its condensate within different closed systems

Answer: a
Clarification: Solar distillation is the use solar energy to evaporate water and collect its condensate within the same closed system. It is important to note that the same system is used to both evaporate and condensate water.

2. Which of the following houses the process of solar distillation?
a) Solar thermo-mechanical system
b) Solar still
c) Photovoltaics
d) Heat engines

Answer: b
Clarification: Solar still houses the process of solar distillation. Solar thermo-mechanical system, photovoltaics and heat engines are not used to perform distillation.

3. Which of the following is a configuration of solar still?
a) Solar panel
b) Solar cell
c) Cone shaped
d) Frustum shaped

Answer: c
Clarification: The three basic configurations of solar still are cone shaped, box-like and frustum shaped. Solar cells and panels are not solar stills and are not used for solar distillation.

4. Which of the following best describes the process of solar distillation?
a) Influent → solar distillation system → salty solute remains → evaporation of volatile solvents as effluents
b) Influent → evaporation of volatile solvents as effluents → solar distillation system → salty solute remains
c) Influent → solar distillation system → evaporation of volatile solvents as effluents → salty solute remains
d) Solar distillation system → influent → evaporation of volatile solvents as effluents → salty solute remains

Answer: d
Clarification: The influent enters the solar distillation system. The volatile solvents evaporate as effluents leaving behind salty solute.

5. Which of the following is an example of solar distillation?
a) Natural water cycle
b) Fractional distillation
c) Reverse osmosis
d) Osmosis

Answer: a
Clarification: Natural water cycle is a very common example of solar distillation that the earth experiences. Fractional distillation, osmosis and reverse osmosis are not solar distillation.

6. What are the two categories of solar still?
a) Active and deactivate
b) Active and passive
c) Box and cone
d) Passive and pit

Answer: b
Clarification: Active and passive are the two main categories of solar still. Box, cone and pit are the basic configurations of solar still.

7. What do the two categories of solar still namely, active and passive depict?
a) The method of evaporation
b) The method of condensation
c) The method of acquiring energy to drive evaporation
d) The method of collecting evaporated water

Answer: c
Clarification: The two categories of solar still depict the method of acquiring energy to drive evaporation. Evaporation, condensation and collection of condensate are performed only after energy is supplied to the system.

8. What is an active solar still?
a) A solar still that solely relies on sun to distill water
b) A solar still that relies only on sun and wind
c) A solar sill that automatically gets activated when sun shines on it
d) A solar still that uses additional heat sources apart from sun

Answer: d
Clarification: An active solar still uses additional heat sources apart from sun. These additional heat sources are used to promote existing thermal processes like initial start-up.

9. Which of the following are examples of active solar stills?
a) Compound Parabolic Concentrators and flat plate collectors
b) Solar heater and photovoltaics
c) Flat plate collectors and heat engines
d) Compound parabolic concentrators and sun

Answer: a
Clarification: Compound parabolic concentrators, flat plate collectors and solar heaters are examples of active solar stills. Photovoltaics and heat engines are not solar stills. Sun is the energy source of solar still.

10. Active stills demote faster and larger quantities of freshwater generation.
a) True
b) False

Answer: b
Clarification: Active stills demote faster and larger quantities of freshwater generation. This comes at the cost of increased design complexity and manufacturing.

11. What is a passive solar still?
a) A solar still that uses photovoltaics to start
b) A solar still that relies only on sun and wind
c) A solar still that solely relies on sun to distill water
d) A solar still that uses additional heat sources apart from sun

Answer: c
Clarification: A passive solar still is a conventional solar still that solely relies on the sun to distill water. Though the process may be slow it generally has a lower design complexity as compared to an active solar still.

12. Which of the following is a type of passive stills?
a) Solar still with compound parabolic concentrator
b) Single-effect stills with flat plate collectors
c) Multi-effect stills with compound parabolic concentrator
d) Single-effect solar still

Answer: d
Clarification: Single-effect and multi-effect solar stills are types of passive stills. However, if any of these systems are attached with additional thermal sources like compound parabolic concentrators and flat plate collectors, they become active solar stills.

13. In a single-effect still, it is crucial to keep the distiller _______
a) airtight
b) aerated
c) connected with another distiller
d) connected with multiple distillers

Answer: a
Clarification: Single-effect stills are the simples and popularly used solar stills. In a single-effect solar still, it is a crucial design challenge to keep the distiller airtight. It uses a single interface to convey the energy and collect the condensate.

14. Neutral stills use seawater greenhouses to create freshwater.
a) False
b) True

Answer: b
Clarification: Neutral stills use seawater greenhouses to create freshwater. They are neutral because the energy that goes into creating freshwater is used to grow plants that promote evaporative cooling of air inside.

15. A good insulator is necessary to reduce thermal losses in solar stills.
a) True
b) False

Answer: a
Clarification: A good insulator is necessary to reduce thermal losses in solar stills. In fact, the insulators should be so good that they can prolong the evaporation to night.

Wind Energy Multiple Choice Questions on “Wind Energy Storage – 1”.

1. Which of the following is a reason for storing wind energy?
a) Wind power generation is not correlated to the demand cycle
b) Wind power generation is correlated to the demand cycle
c) Wind is a renewable resource
d) Wind power is guaranteed to be available during peak demands

Answer: a
Clarification: Most of the electricity produced from the plants is consumed immediately. Moreover, wind power generation is not correlated to the demand cycle. It is also not guaranteed to be available during peak demands. Thus, wind power storage is necessary.

2. Which of the following methods are used to store wind energy?
a) Glowing a bulb
b) Electro-chemical
c) Running a consumer electrical appliance
d) Turning off consumer electrical appliances when not in use

Answer: b
Clarification: Wind energy can be stored as electro-chemical energy in the form of batteries. Glowing a bulb and running a consumer electrical appliance consumes energy. While turning off an appliance when not in use saves energy, it doesn’t store energy.

3. What is an example of storing wind power electro-chemically?
a) Electro-hydrogen generation
b) Pumped storage
c) Batteries
d) Electric grid

Answer: c
Clarification: Storing energy in batteries is the most common and simplest method to store wind energy. An electric grid is an interconnected network for delivering power from suppliers to consumers.

4. _________ is an example of storing wind energy chemically.
a) Flywheels
b) Pumped storage
c) Batteries
d) Electro-hydrogen generation

Answer: d
Clarification: Electro-hydrogen is an example of storing wind energy chemically. Batteries typically come under the category of electro-chemical storage. Flywheels come under the category of mechanical storage.

5. Wind energy can be switched on ‘on demand’.
a) True
b) False

Answer: b
Clarification: Wind energy cannot be switched on ‘on demand’. It is inherently intermitted, variable and non-dispatchable. To match the supply with demand, it requires a backup to store the generated power.

6. Energy storage devices can manage power fluctuations.
a) True
b) False

Answer: a
Clarification: Energy storage devices can manage power fluctuations, particularly from renewable sources of energy – wind and solar. Thus, they enable such fluctuating and irregular technologies to cope with consumer’s demand.

7. Which of following is are parameters used to describe an energy storage device?
a) Power, energy, time, frequency, Young’s modulus
b) Power capacity, voltage, heat, angular speed, frequency
c) Power capacity, energy storage capacity, efficiency, response time, round-trip efficiency
d) Stress, strain, Young’s Modulus, elasticity, rigidity

Answer: c
Clarification: Power capacity, energy storage capacity, efficiency, response time and round-trip efficiency are generally used to describe an energy storage device. Stress, strain, Young’s modulus, elasticity and rigidity are used to describe a material. The other options are not used to describe ‘storage potential/capacity’.

8. What is energy storage capacity?
a) Power stored
b) Amount of energy that can be drawn from a storage device
c) Amount of energy stored in a storage device
d) Amount of energy a storage device can store for a period of time

Answer: d
Clarification: Energy storage capacity is the amount of energy a storage device can store for a period of time. It is usually measured in kilowatt-hours (KWh) or megawatt-hours (MWh). It is not the same as amount of energy stored.

9. Pumped hydroelectric is an example of _________
a) Gravitational potential storage
b) Latent heat storage
c) Thermal storage
d) Hydroelectric power generation

Answer: a
Clarification: Pumped hydroelectric storage is an example of gravitational potential storage. It is the most mature storage technique and has the largest storage capacity. For optimization, the pump and the turbine are combined into a single device.

10. What type of materials are used for latent heat storage?
a) Materials with high stress
b) Phase-change materials
c) Materials with high stress/strain ratio
d) Elastic materials

Answer: b
Clarification: Phase change materials are used for latent heat storage. Stress and strain are used to describe a material’s deformation ability. Elastic materials are those which when deformed regain their original shape.

11. Flywheels are an example of ________ energy storage.
a) potential
b) electric potential
c) thermal kinetic
d) kinetic

Answer: d
Clarification: Flywheels are an example of storing mechanical energy in the form of kinetic energy. The flywheel (or rotor) is accelerated to a high speed thus maintaining the energy. The energy is stored in the system in the form of rotational kinetic energy.

12. When does a power conversion system act as a rectifier for an energy storing device?
a) When the device is being charged
b) When the device is being discharged
c) When the device stops working
d) When the power conversion system is being charged

Answer: a
Clarification: A power conversion system acts as a rectifier when the energy storing device is being charged. This is because any existing energy storage cannot store AC. Except for mechanical storage devices, it is necessary to convert alternating current (AC) to direct current (DC) and vice-versa.

13. When does a power conversion system act as an inverter for an energy storing device?
a) When the device is being charged
b) When the device is being discharged
c) When the device starts working
d) When the power conversion system is being discharged

Answer: b
Clarification: A power conversion system acts as an inverter when the energy storing device is being discharged. The converted AC current is then transported to the consumer. Transporting alternating currents reduces the amount of resistive losses.

14. Which of the following parameters are used to describe rechargeable batteries?
a) Power
b) Frequency
c) Charge-to-discharge ratio
d) Angular speed

Answer: c
Clarification: Charge-to-discharge ratio, depth of discharge (DoD) and memory effect are commonly used to describe rechargeable batteries. Power, frequency and angular speed are not used to describe any storage device’s characteristics.

15. Capacitors store energy in the form of ________
a) potential
b) AC voltage
c) thermal potential
d) electric potential

Answer: d
Clarification: Capacitors store energy in the form of electric potential. The energy is stored between two metallic plates. Neither AC voltage nor alternating current can be stored.

Geothermal Energy Multiple Choice Questions on “Environmental Consideration”.

1. Which of the following is a problem with a geothermal resource?
a) Noise pollution
b) Low greenhouse gas emission
c) Polluting water
d) Reversing damage to wildlife habitat
Answer: a
Clarification: Noise pollution is one of the major problems caused due to establishment of a power plant near a geothermal resource. Also, the plant continuously uses and reuses water for cooling thereby affecting the local fresh water resources. It does not pollute water.

2. Which of the following gases are released by a geothermal power plant?
a) Carbon
b) Sulphur
c) Sulphate
d) Argon
Answer: b
Clarification: Sulphur, hydrogen sulphide and oxides of nitrogen and sulphur are released by a geothermal power plant. All these gases are harmful as they cause acid rain. Carbon is not a gas. Sulphates exist in liquid or solid form.

3. Why do binary power plants emit less amounts of pollutants?
a) Because they release steam into the atmosphere
b) Because they release steam into a local water body
c) Because they inject water back into the ground without any atmospheric exposition
d) Because they inject water back into the ground after atmospheric exposition
Answer: c
Clarification: Binary power plants emit less amounts of pollutants because they inject water back into the ground without any atmospheric exposition. They also treat the steam before releasing into the atmosphere.

4. Which of the following best describes the cause for noise pollution due to a geothermal power plant?
a) Emission of gases
b) Ecological destruction
c) Damaging wildlife habitat
d) Drilling wells
Answer: d
Clarification: Drilling wells is the major cause of noise pollution due to geothermal power plants. The other options do not cause noise pollution. Drilling may also affect wildlife habitat and ecology.

5. Geothermal plants use about 20L of fresh water per MWh.
a) True
b) False
Answer: a
Clarification: Geothermal plants use about 20L of fresh water per MWh. This is negligible when compared to coal plants which use about 1370L of fresh water per MWh.

6. ________ water is used by The Geysers facility in California.
a) Fresh
b) Waste
c) Hot
d) Cold
Answer: b
Clarification: Waste water is used by The Geysers facility in California for cooling purposes. In fact, the geothermal plant also treats the water and injects it back into the reservoir thereby reducing surface pollution.

7. What are the two main land use problems due to a geothermal power plant?
a) Minor earthquakes
b) Minor earthquakes and greenhouse gas emissions
c) Minor earthquakes and subsidence
d) Removal of magma and subsidence
Answer: c
Clarification: The two main land use problems due to geothermal power plants are induced seismicity (minor earthquakes) and subsidence. Subsidence is gradual caving in of land. Geothermal power plants do not add to greenhouse gas emissions. As a matter of fact, this is not related to land use problems.

8. How are subsidence and induced seismicity mitigated?
a) By removing the fluid
b) By removing the gas
c) By drilling deeper wells
d) By injecting spent fluid back into the reservoir
Answer: d
Clarification: Subsidence and induced seismicity are caused by removal of the fluid present in the reservoir. They can be mitigated by injecting spent fluid back into the reservoir. Drilling deeper wells will only add to the problem.

9. Geothermal plants are located near the reservoir.
a) False
b) True
Answer: a
Clarification: Geothermal plants are located far away from the reservoir. This is done to prevent impacts on the reservoir due to extraction of fluid.

10. Which of the following geothermal power plants have no significant impact on natural features.
a) Binary cycle
b) Direct use
c) High temperature
d) Coal
Answer: b
Clarification: Direct use geothermal power plants have no significant impact on its surroundings. This is because it is small and directly use the fluid present in the reservoir without any (or much) auxiliary processing. Coal power plant is not a geothermal power plant.

11. Utilizing geothermal resources eliminates _________
a) sulphur emissions
b) usage of power grid
c) mining
d) earthquakes
Answer: c
Clarification: Utilizing geothermal resources eliminates mining and transportation of electricity. It uses power grid to distribute the generated electricity to the consumers. Sulphur emissions and earthquakes are the problems caused due to geothermal power plants.

12. If a geothermal power plant is located near a reservoir, fluid from _______ reservoir is used.
a) the same
b) another neighbouring
c) coal
d) another far away
Answer: d
Clarification: If a geothermal power plant is located near a reservoir, fluid from another far away reservoir is used. This is to prevent unwanted impacts on the reservoir near the plant’s location.

13. Which of the following is most responsible for increasing usage of geothermal power plants?
a) Efficient heat pumps
b) More sites
c) Less sites
d) Poor heat pumps
Answer: a
Clarification: Efficient heat pumps are responsible for increasing usage of geothermal power plants across the globe. Heat pumps transfer heat energy from a source of heat to a thermal reservoir (not same as geothermal reservoir).

14. Which of the following countries mainly use “direct-use” geothermal.
a) United States
b) Iceland
c) Iran
d) Greenland
Answer: b
Clarification: Iceland is a nation built on about 130 volcanoes. It rests above a divergent plate boundary which brings continuous supply magma. Along with Turkey, it mainly uses “direct-use” geothermal energy.

15. Impacts on land, impacts on surrounding environment and gaseous emissions are the three main problems due to geothermal power plants.
a) True
b) False
Answer: a
Clarification: Impacts on land, impacts on surrounding environment and gaseous emissions are the three main problems due to geothermal power plants. While impacts on surrounding environment is regulated by a detailed survey of the area, the gaseous emissions are being mitigated by pre-treatment of effluents.

Education & Learning Series – Geothermal Energy.

Geothermal Energy,
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