Real Texas General Pump Installer Practice
Exam – Full Course 2026 Edition (TDLR–
Approved Format | 300 Questions with Answers
& Detailed Rationales) PDF
Domain 1: Pump Types & Fundamental Operating Principles (Questions 1-
30)
1. Which type of pump is most commonly used for high-volume, low-
pressure applications?
A. Positive displacement pump
B. Submersible pump
C. Jet pump
D. Centrifugal pump
Answer: D. Centrifugal pump
Rationale: Centrifugal pumps are designed to handle high flow rates at
moderate pressures by converting rotational kinetic energy into
hydrodynamic energy using an impeller. This makes them ideal for
applications like irrigation and water transfer where volume is prioritized
over high pressure .
2. What is the primary operating principle behind a centrifugal pump?
A. Fluid displacement by a piston
B. Creation of a vacuum through the Venturi effect
C. Conversion of rotational energy into kinetic energy using centrifugal force
D. Compression of air to force water upward
Answer: C. Conversion of rotational energy into kinetic energy using
centrifugal force
Rationale: A centrifugal pump uses a rotating impeller to impart velocity to
the fluid. The high-speed rotation creates centrifugal force, flinging the
water outward, which is then converted into pressure energy in the volute
casing .
,3. Which type of pump is typically required for a deep well with a static
water level of 300 feet?
A. Shallow well jet pump
B. Deep well jet pump
C. Centrifugal pump
D. Submersible pump
Answer: D. Submersible pump
*Rationale: Submersible pumps are installed below the water level and push
water to the surface, making them highly efficient for deep wells (exceeding
100 feet). Jet pumps, even deep-well models, struggle with suction lift
beyond approximately 100-150 feet in practice .*
4. What is the function of the Venturi in a jet pump?
A. To cool the motor
B. To create a low-pressure zone to draw water from the well
C. To filter debris before it enters the impeller
D. To increase the electrical efficiency of the motor
Answer: B. To create a low-pressure zone to draw water from the well
Rationale: In a jet pump, a portion of the water is recirculated through a
nozzle and venturi. The nozzle accelerates water, and as it passes through
the venturi, it creates a pressure drop (suction) that lifts water from the
well .
5. A positive displacement pump is best suited for which scenario?
A. Transferring large volumes of water for irrigation
B. High-pressure, low-flow applications such as chemical injection
C. Pumping from a deep well with a 4-inch casing
D. Circulating water in a swimming pool
Answer: B. High-pressure, low-flow applications such as chemical injection
Rationale: Unlike centrifugal pumps, positive displacement pumps trap a
fixed amount of fluid and force it into the discharge pipe. This allows them
to maintain a consistent flow rate regardless of pressure, making them ideal
for precise applications like dosing chemicals or high-pressure cleaning .
,6. What does the term "pump head" refer to?
A. The physical height of the pump assembly
B. The diameter of the pump impeller
C. The total height a pump can raise water, measured in feet or meters
D. The maximum current draw of the motor
Answer: C. The total height a pump can raise water, measured in feet or
meters
Rationale: Head is a measure of the energy imparted to the fluid by the
pump. It represents the height of a water column that the pump can
overcome, accounting for vertical lift and friction losses .
7. What is the purpose of the volute casing in a centrifugal pump?
A. To house the electrical connections
B. To direct fluid from the impeller to the discharge pipe while converting
velocity into pressure
C. To serve as a reservoir for pump lubricant
D. To prevent cavitation by cooling the impeller
Answer: B. To direct fluid from the impeller to the discharge pipe while
converting velocity into pressure
Rationale: The volute is the spiral-shaped casing surrounding the impeller.
Its gradually increasing cross-sectional area slows down the fluid velocity,
converting that kinetic energy into static pressure (head) before the water
exits the pump .
8. If a centrifugal pump is operating far to the right of its Best Efficiency
Point (BEP) on its curve, what is likely to happen?
A. Maximum efficiency and minimal vibration
B. Cavitation due to insufficient NPSH
C. High vibration, reduced efficiency, and potential motor overload
D. The pump will automatically shut down to prevent damage
Answer: C. High vibration, reduced efficiency, and potential motor overload
Rationale: Operating a pump outside its BEP causes hydraulic imbalances. At
high flow rates (right of BEP), recirculation and turbulence occur, leading to
, vibration, increased bearing wear, reduced efficiency, and higher power
consumption, which can overload the motor .
9. What is the primary effect of increasing the diameter of the impeller on a
centrifugal pump?
A. Flow rate decreases significantly
B. Both flow rate and head increase
C. Head decreases while efficiency increases
D. The pump requires less horsepower
Answer: B. Both flow rate and head increase
Rationale: According to the pump affinity laws, increasing the impeller
diameter (at constant speed) increases both the flow rate (proportional to
the diameter) and the head (proportional to the square of the diameter).
This is a common way to adjust pump performance .
10. What does a pump performance curve show?
A. The relationship between voltage and amperage draw
B. The relationship between flow rate (Q) and head (H)
C. The relationship between pump age and efficiency
D. The relationship between water temperature and viscosity
Answer: B. The relationship between flow rate (Q) and head (H)
Rationale: A pump curve is a graphical representation of a pump's ability to
generate head at various flow rates. It is the fundamental tool used to select
a pump that meets the system's hydraulic requirements (Total Dynamic
Head) at the desired flow rate .
11. Which component in a pump system prevents the water from flowing
backward when the pump stops?
A. Gate valve
B. Pressure relief valve
C. Check valve
D. Flow control valve
Answer: C. Check valve
Rationale: Check valves are one-way valves. In a pumping system, they
Exam – Full Course 2026 Edition (TDLR–
Approved Format | 300 Questions with Answers
& Detailed Rationales) PDF
Domain 1: Pump Types & Fundamental Operating Principles (Questions 1-
30)
1. Which type of pump is most commonly used for high-volume, low-
pressure applications?
A. Positive displacement pump
B. Submersible pump
C. Jet pump
D. Centrifugal pump
Answer: D. Centrifugal pump
Rationale: Centrifugal pumps are designed to handle high flow rates at
moderate pressures by converting rotational kinetic energy into
hydrodynamic energy using an impeller. This makes them ideal for
applications like irrigation and water transfer where volume is prioritized
over high pressure .
2. What is the primary operating principle behind a centrifugal pump?
A. Fluid displacement by a piston
B. Creation of a vacuum through the Venturi effect
C. Conversion of rotational energy into kinetic energy using centrifugal force
D. Compression of air to force water upward
Answer: C. Conversion of rotational energy into kinetic energy using
centrifugal force
Rationale: A centrifugal pump uses a rotating impeller to impart velocity to
the fluid. The high-speed rotation creates centrifugal force, flinging the
water outward, which is then converted into pressure energy in the volute
casing .
,3. Which type of pump is typically required for a deep well with a static
water level of 300 feet?
A. Shallow well jet pump
B. Deep well jet pump
C. Centrifugal pump
D. Submersible pump
Answer: D. Submersible pump
*Rationale: Submersible pumps are installed below the water level and push
water to the surface, making them highly efficient for deep wells (exceeding
100 feet). Jet pumps, even deep-well models, struggle with suction lift
beyond approximately 100-150 feet in practice .*
4. What is the function of the Venturi in a jet pump?
A. To cool the motor
B. To create a low-pressure zone to draw water from the well
C. To filter debris before it enters the impeller
D. To increase the electrical efficiency of the motor
Answer: B. To create a low-pressure zone to draw water from the well
Rationale: In a jet pump, a portion of the water is recirculated through a
nozzle and venturi. The nozzle accelerates water, and as it passes through
the venturi, it creates a pressure drop (suction) that lifts water from the
well .
5. A positive displacement pump is best suited for which scenario?
A. Transferring large volumes of water for irrigation
B. High-pressure, low-flow applications such as chemical injection
C. Pumping from a deep well with a 4-inch casing
D. Circulating water in a swimming pool
Answer: B. High-pressure, low-flow applications such as chemical injection
Rationale: Unlike centrifugal pumps, positive displacement pumps trap a
fixed amount of fluid and force it into the discharge pipe. This allows them
to maintain a consistent flow rate regardless of pressure, making them ideal
for precise applications like dosing chemicals or high-pressure cleaning .
,6. What does the term "pump head" refer to?
A. The physical height of the pump assembly
B. The diameter of the pump impeller
C. The total height a pump can raise water, measured in feet or meters
D. The maximum current draw of the motor
Answer: C. The total height a pump can raise water, measured in feet or
meters
Rationale: Head is a measure of the energy imparted to the fluid by the
pump. It represents the height of a water column that the pump can
overcome, accounting for vertical lift and friction losses .
7. What is the purpose of the volute casing in a centrifugal pump?
A. To house the electrical connections
B. To direct fluid from the impeller to the discharge pipe while converting
velocity into pressure
C. To serve as a reservoir for pump lubricant
D. To prevent cavitation by cooling the impeller
Answer: B. To direct fluid from the impeller to the discharge pipe while
converting velocity into pressure
Rationale: The volute is the spiral-shaped casing surrounding the impeller.
Its gradually increasing cross-sectional area slows down the fluid velocity,
converting that kinetic energy into static pressure (head) before the water
exits the pump .
8. If a centrifugal pump is operating far to the right of its Best Efficiency
Point (BEP) on its curve, what is likely to happen?
A. Maximum efficiency and minimal vibration
B. Cavitation due to insufficient NPSH
C. High vibration, reduced efficiency, and potential motor overload
D. The pump will automatically shut down to prevent damage
Answer: C. High vibration, reduced efficiency, and potential motor overload
Rationale: Operating a pump outside its BEP causes hydraulic imbalances. At
high flow rates (right of BEP), recirculation and turbulence occur, leading to
, vibration, increased bearing wear, reduced efficiency, and higher power
consumption, which can overload the motor .
9. What is the primary effect of increasing the diameter of the impeller on a
centrifugal pump?
A. Flow rate decreases significantly
B. Both flow rate and head increase
C. Head decreases while efficiency increases
D. The pump requires less horsepower
Answer: B. Both flow rate and head increase
Rationale: According to the pump affinity laws, increasing the impeller
diameter (at constant speed) increases both the flow rate (proportional to
the diameter) and the head (proportional to the square of the diameter).
This is a common way to adjust pump performance .
10. What does a pump performance curve show?
A. The relationship between voltage and amperage draw
B. The relationship between flow rate (Q) and head (H)
C. The relationship between pump age and efficiency
D. The relationship between water temperature and viscosity
Answer: B. The relationship between flow rate (Q) and head (H)
Rationale: A pump curve is a graphical representation of a pump's ability to
generate head at various flow rates. It is the fundamental tool used to select
a pump that meets the system's hydraulic requirements (Total Dynamic
Head) at the desired flow rate .
11. Which component in a pump system prevents the water from flowing
backward when the pump stops?
A. Gate valve
B. Pressure relief valve
C. Check valve
D. Flow control valve
Answer: C. Check valve
Rationale: Check valves are one-way valves. In a pumping system, they
