Worksheets3-1 RES IT-C 2025-26_Unit-3-A
Total questions: 60
Worksheet time: 30mins
Which of the following is not a biochemical conversion process of biomass?
Fermentation
Pyrolysis
Anaerobic digestion
Composting
The primary component responsible for energy content in biomass is:
Cellulose
Hemicellulose
Lignin
Carbon
The C/N ratio most suitable for efficient biomass digestion is approximately:
10:1
30:1
45:1
5:1
The calorific value of dry biomass generally lies in the range of:
5–10 MJ/kg
15–20 MJ/kg
25–30 MJ/kg
30–40 MJ/kg
Which of the following best describes “Biomass Conversion Efficiency”?
Ratio of total energy input to total energy output
Ratio of usable energy output to total biomass energy content
Ratio of carbon content to nitrogen content
Ratio of mass converted to total input
6. Which conversion route primarily involves high temperature in the absence of oxygen?
Combustion
Fermentation
Gasification
Pyrolysis
In a biogas plant, the process of methane formation is known as:
Acidogenesis
Methanogenesis
Hydrolysis
Acetogenesis
The gas composition of biogas typically contains methane in the range of:
10–20%
25–35%
50–70%
80–90%
. Which thermochemical process produces both char and gas as main products?
Combustion
Gasification
Pyrolysis
Anaerobic digestion
In gasification, the main combustible gases produced are:
CO, CO₂, CH₄, H₂
CO₂, O₂, N₂
CH₄, NH₃, H₂S
CO, H₂, N₂, O₂
During photosynthesis, the light-dependent reactions take place in the:
Stroma
Thylakoid membrane
Cytoplasm
Mitochondria
The overall balanced equation of photosynthesis can be represented as:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
CO₂ + H₂O → CH₄ + O₂
6CO₂ + 6H₂O → C₂H₅OH + O₂
6CO₂ + 12H₂O → C₆H₁₂O₆ + 12O₂
Which pigment in plants directly participates in the light reaction of photosynthesis?
Carotene
Chlorophyll a
Chlorophyll b
Xanthophyll
The enzyme responsible for carbon fixation in the Calvin cycle is:
ATP synthase
NADP reductase
Pyruvate dehydrogenase
The quantum requirement (number of photons required to produce one molecule of O₂) in photosynthesis is approximately:
2
4
8
16
The optimal pH range for anaerobic digestion is:
3.0–5.0
5.5–7.0
6.8–7.2
8.0–9.0
High ammonia concentration in the digester primarily inhibits:
Hydrolytic bacteria
Acidogenic bacteria
Methanogenic bacteria
Acetogenic bacteria
The temperature range suitable for mesophilic digestion is:
20–30°C
30–40°C
50–60°C
60–70°C
The process that converts complex organic polymers into simple sugars during digestion is:
Methanogenesis
Hydrolysis
Acidogenesis
Acetogenesis
Which of the following conditions reduces the rate of biogas production?
High moisture content
Optimal temperature
High lignin content
Balanced C/N ratio
The primary form of energy converted in a hydroelectric power plant is------------------------
Kinetic energy → Mechanical → Electrical
Potential energy → Kinetic → Mechanical → Electrical
Mechanical → Thermal → Electrical
Chemical → Electrical
The head in a hydro-power plant represents-------------------
Volume of water stored
Vertical height difference between water levels
Flow velocity of water
Pressure at turbine inlet
In a hydro plant, the component that converts kinetic energy of water into mechanical energy is---------
Generator
Turbine
Dam
Surge tank
The primary role of the penstock in a hydropower system is to-------------------------
Store water
Control voltage output
Convey water under pressure to the turbine
Increase the head of the plant
Based on load factor, hydropower plants are categorized as------------------------
Run-of-river and pumped storage
Base load and peak load plants
High head and low head plants
Storage and micro plants
In a run-of-river hydro system------------------
Large storage reservoir is essential
Water is used immediately after it arrives
There is no turbine used
Pumped storage is mandatory
The main advantage of pumped-storage hydel plants is-----------------
Lower capital cost
Simple design
Energy storage during off-peak hours
No need for transmission lines
Which type of hydro system is best suited for isolated rural electrification?
High head hydro plant
Pumped storage plant
Small hydropower plant
Reservoir-based large hydro plant
11. According to the Central Electricity Authority (India), small hydropower plants have a capacity up to:
10 MW
50 MW
100 MW
25 MW
Which of the following is not a major component of a small hydel plant?
Boiler
Spillway
Draft tube
Turbine
The efficiency of small hydro turbines typically lies between------------
30–40%
75–90%
90–95%
50–60%
The specific speed of a turbine helps in:
Determining the penstock length
Calculating generator efficiency
Designing the dam structure
Selecting the type of turbine suitable for head and discharge
A Pelton wheel turbine is suitable for:
High head, low discharge
Low head, high discharge
Medium head, medium discharge
Low head, low discharge
Francis turbine is generally used for:
Medium head
High head
Low head
Variable head
Kaplan turbines are suitable for:
Medium head, medium discharge
Very high head
High head, low discharge
Low head, high discharge
In small hydel projects, the major cost component is usually:
Turbine
Generator
Civil works
Penstock
In small hydel projects, the major cost component is usually:
Civil works
Generator
Turbine
Penstock
The main limitation of large hydel plants compared to small ones is:
High ecological and social impact
High transmission losses
Low efficiency
Shorter lifespan
Which of the following statements is true regarding small hydro plants?
They have high construction time and cost.
They depend entirely on fossil fuels.
They can operate as grid-connected or isolated systems.
They require large reservoirs.
Which of the following statements is true regarding small hydro plants?
They have high construction time and cost.
They depend entirely on fossil fuels.
They can operate as grid-connected or isolated systems.
They require large reservoirs.
The term “geothermal” literally refers to:
Heat from the Earth’s core
Heat stored in oceans
Solar heat absorbed by land
Heat released during earthquakes
The approximate geothermal gradient (average temperature increase per km depth) in Earth’s crust is:
10°C/km
25–30°C/km
50°C/km
70°C/km
The primary source of geothermal energy is:
Solar radiation
Chemical decomposition of rocks
Radioactive decay of isotopes in the Earth's crust
Atmospheric pressure difference
The majority of usable geothermal resources are found in which region of the Earth’s crust?
Inner core
Outer core
Upper 10 km of the crust
Mantle transition zone
The “Ring of Fire” is important for geothermal energy because:
It has high wind speed zones
It contains the largest geothermal activity on Earth
It provides solar radiation all year
It has the lowest tectonic activity
A hydrothermal system consists of:
Dry rock without fluid
Magma only
Hot water or steam trapped in permeable rock formations
Frozen water beneath the crust
. Which of the following geothermal resource types directly produces dry steam for power generation?
Hot water reservoirs
Vapour-dominated reservoirs
Geo-pressured systems
Hot dry rock systems
The enthalpy of geothermal resources is used to classify them as:
High, medium, and low enthalpy resources
Wet and dry resources
Open and closed system resources
Surface and deep resources
Hot dry rock (HDR) geothermal systems primarily require:
Natural fluid flow
Enhanced fluid injection and fracturing
Natural geysers
Sedimentary basins
A geo-pressured geothermal resource is characterized by:
Superheated dry steam
High-pressure water with dissolved methane
Low-temperature saline water
High-viscosity mud
The world’s first geothermal power plant was commissioned in:
1904, Larderello (Italy)
1925, New Zealand
1952, Iceland
1960, California
Binary cycle geothermal plants are best suited for:
Low-temperature geothermal resources
Only high-temperature vapour fields
Geopressured systems
Marine geothermal vents
Direct utilization of geothermal energy does not include:
Space heating
Greenhouse heating
Desalination
Hydroelectric generation
A flash steam power plant operates by:
Using low-pressure water to evaporate
Flashing high-pressure hot water into steam
Injecting water into cold rock
Condensing steam from atmosphere
The efficiency of geothermal power plants is generally lower (10–20%) than that of fossil-fuel plants because:
Geothermal fluids are at lower temperatures
Turbines are smaller
Fluids contain impurities
The Earth’s core heat fluctuates
The scaling problem in geothermal plants is mainly caused by:
High flow velocity
Microbial growth
Steam condensation
Dissolved minerals precipitating as water cools
The corrosion of pipes and turbines in geothermal systems mainly occurs due to:
High salinity and presence of H₂S and CO₂ gases
Excessive temperature fluctuations
Mechanical erosion
High pH water
One major environmental issue unique to geothermal systems is:
Greenhouse gas emissions from combustion
Surface subsidence due to fluid withdrawal
Air pollution from ash particles
Radiation leakage
The odor problem associated with geothermal power plants is due to:
CO₂
H₂S (Hydrogen Sulfide) emissions
SO₂
CH₄
Reinjection of used geothermal fluids into the reservoir helps primarily to:
Increase turbine efficiency
Maintain reservoir pressure and reduce pollution
Increase steam temperature
Reduce drilling costs
