TEXAS WASTEWATER CLASS D NEWEST ACTUAL EXAM COMPLETE 300 QESTIONS
AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Question 1
Water moves upward through xylem cells in plants by which mechanism?
A) Gravitational pull
B) Capillary action
C) Evaporation
D) Photosynthesis
Correct Answer: B) Capillary action
Rationale: Capillary action describes the ability of a liquid to flow in narrow spaces
without the assistance of, or even in opposition to, external forces like gravity. This allows
water to move upward through the plant's xylem cells.
Question 2
Plants release water vapor into the atmosphere through specialized cell openings called:
A) Xylem
B) Roots
C) Stomata
D) Follicles
Correct Answer: C) Stomata
Rationale: Plants transpire (release water vapor) through openings in the leaves known as
stomata.
Question 3
What is the approximate molecular weight of water?
A) 12 grams/mole
B) 16 grams/mole
C) 18 grams/mole
D) 24 grams/mole
Correct Answer: C) 18 grams/mole
Rationale: Water (H2O) has a molecular weight of approximately 18 grams/mole (2 grams
for Hydrogen + 16 grams for Oxygen).
, 2
Question 4
In terms of electrical conductivity, pure water is considered a:
A) Superconductor
B) Good conductor
C) Semiconductor
D) Poor conductor
Correct Answer: D) Poor conductor
Rationale: Pure water lacks dissolved ions and minerals, making it a poor conductor of
electricity.
Question 5
The water found in oceans represents approximately what percentage of the world’s total
water inventory?
A) 50%
B) 75%
C) 89%
D) 97%
Correct Answer: D) 97%
Rationale: The vast majority of the Earth's water, about 97%, is saline water located in the
oceans.
Question 6
One acre-foot of water is equivalent to approximately how many gallons?
A) 43,560
B) 100,000
C) 325,851
D) 1,000,000
Correct Answer: C) 325,851
Rationale: An acre-foot is a unit of volume commonly used in water management, equal to
approximately 325,851 gallons.
, 3
Question 7
Approximately what percentage of precipitation falling on Texas returns to the atmosphere
via evapotranspiration?
A) 10%
B) 50%
C) 89%
D) 97%
Correct Answer: C) 89%
Rationale: In the Texas hydrological cycle, about 89% of annual precipitation is lost back
to the atmosphere through evapotranspiration.
Question 8
Water moves from the surface, through the ground, and into aquifers by a process known
as:
A) Transpiration
B) Percolation
C) Evaporation
D) Precipitation
Correct Answer: B) Percolation
Rationale: Percolation is the movement of water through the soil and porous rock to
replenish aquifers.
Question 9
Statewide, total water usage is about 16 million acre-feet per year. The majority of this
water is used for:
A) Domestic drinking water
B) Industrial cooling
C) Irrigation
D) Wastewater transport
Correct Answer: C) Irrigation
Rationale: Agricultural irrigation is the largest consumer of water in the state.
, 4
Question 10
On average, the composition of domestic sewage is broken down into which ratio?
A) 50% residential; 50% commercial
B) 2/3 residential; 1/3 commercial and institutional
C) 1/3 residential; 2/3 industrial
D) 90% residential; 10% commercial
Correct Answer: B) 2/3 residential; 1/3 commercial and institutional
Rationale: Typical domestic sewage flow is attributed two-thirds to residential sources and
one-third to commercial/institutional sources.
Question 11
When original sewer systems were first built, where was the sewage typically discharged?
A) Treatment lagoons
B) Rivers or streams
C) Deep injection wells
D) Sanitary landfills
Correct Answer: B) Rivers or streams
Rationale: Before modern treatment standards, raw sewage was collected and discharged
directly into nearby bodies of water like rivers or streams.
Question 12
Dr. Karl Imhoff designed the Imhoff tank in Germany in what year?
A) 1850
B) 1906
C) 1945
D) 1972
Correct Answer: B) 1906
Rationale: The Imhoff tank, a primary treatment device, was introduced by Dr. Karl
Imhoff in 1906.
AND CORRECT DETAILED ANSWERS (VERIFIED ANSWERS) |ALREADY GRADED A+
Question 1
Water moves upward through xylem cells in plants by which mechanism?
A) Gravitational pull
B) Capillary action
C) Evaporation
D) Photosynthesis
Correct Answer: B) Capillary action
Rationale: Capillary action describes the ability of a liquid to flow in narrow spaces
without the assistance of, or even in opposition to, external forces like gravity. This allows
water to move upward through the plant's xylem cells.
Question 2
Plants release water vapor into the atmosphere through specialized cell openings called:
A) Xylem
B) Roots
C) Stomata
D) Follicles
Correct Answer: C) Stomata
Rationale: Plants transpire (release water vapor) through openings in the leaves known as
stomata.
Question 3
What is the approximate molecular weight of water?
A) 12 grams/mole
B) 16 grams/mole
C) 18 grams/mole
D) 24 grams/mole
Correct Answer: C) 18 grams/mole
Rationale: Water (H2O) has a molecular weight of approximately 18 grams/mole (2 grams
for Hydrogen + 16 grams for Oxygen).
, 2
Question 4
In terms of electrical conductivity, pure water is considered a:
A) Superconductor
B) Good conductor
C) Semiconductor
D) Poor conductor
Correct Answer: D) Poor conductor
Rationale: Pure water lacks dissolved ions and minerals, making it a poor conductor of
electricity.
Question 5
The water found in oceans represents approximately what percentage of the world’s total
water inventory?
A) 50%
B) 75%
C) 89%
D) 97%
Correct Answer: D) 97%
Rationale: The vast majority of the Earth's water, about 97%, is saline water located in the
oceans.
Question 6
One acre-foot of water is equivalent to approximately how many gallons?
A) 43,560
B) 100,000
C) 325,851
D) 1,000,000
Correct Answer: C) 325,851
Rationale: An acre-foot is a unit of volume commonly used in water management, equal to
approximately 325,851 gallons.
, 3
Question 7
Approximately what percentage of precipitation falling on Texas returns to the atmosphere
via evapotranspiration?
A) 10%
B) 50%
C) 89%
D) 97%
Correct Answer: C) 89%
Rationale: In the Texas hydrological cycle, about 89% of annual precipitation is lost back
to the atmosphere through evapotranspiration.
Question 8
Water moves from the surface, through the ground, and into aquifers by a process known
as:
A) Transpiration
B) Percolation
C) Evaporation
D) Precipitation
Correct Answer: B) Percolation
Rationale: Percolation is the movement of water through the soil and porous rock to
replenish aquifers.
Question 9
Statewide, total water usage is about 16 million acre-feet per year. The majority of this
water is used for:
A) Domestic drinking water
B) Industrial cooling
C) Irrigation
D) Wastewater transport
Correct Answer: C) Irrigation
Rationale: Agricultural irrigation is the largest consumer of water in the state.
, 4
Question 10
On average, the composition of domestic sewage is broken down into which ratio?
A) 50% residential; 50% commercial
B) 2/3 residential; 1/3 commercial and institutional
C) 1/3 residential; 2/3 industrial
D) 90% residential; 10% commercial
Correct Answer: B) 2/3 residential; 1/3 commercial and institutional
Rationale: Typical domestic sewage flow is attributed two-thirds to residential sources and
one-third to commercial/institutional sources.
Question 11
When original sewer systems were first built, where was the sewage typically discharged?
A) Treatment lagoons
B) Rivers or streams
C) Deep injection wells
D) Sanitary landfills
Correct Answer: B) Rivers or streams
Rationale: Before modern treatment standards, raw sewage was collected and discharged
directly into nearby bodies of water like rivers or streams.
Question 12
Dr. Karl Imhoff designed the Imhoff tank in Germany in what year?
A) 1850
B) 1906
C) 1945
D) 1972
Correct Answer: B) 1906
Rationale: The Imhoff tank, a primary treatment device, was introduced by Dr. Karl
Imhoff in 1906.
