CWEA MECHANICAL TECHNOLOGIST
GRADE EXAM 2026/2027 QUESTIONS
AND VERIFIED ANSWERS
1. What is the primary cause of cavitation in a centrifugal pump?
A. Suction pressure dropping below the liquid’s vapor pressure
B. High discharge pressure
C. Excessive pump speed
D. Misalignment of the pump and motor
Answer: A
Conceptual Explanation: Cavitation occurs when the local pressure at the impeller eye
drops below the vapor pressure of the liquid, causing bubbles to form and then collapse
violently.
2. According to Pump Affinity Laws, how does the required horsepower change if the pump
speed is doubled?
A. It increases by eight times
B. It increases by four times
C. It doubles
D. It remains the same
,Answer: A
Conceptual Explanation: Horsepower varies with the cube of the speed change (2 to the
power of 3 = 8).
3. Which type of bearing is specifically designed to handle axial loads only?
A. Radial ball bearing
B. Thrust bearing
C. Needle bearing
D. Tapered roller bearing
Answer: B
Conceptual Explanation: Thrust bearings are designed to support loads that act parallel
to the axis of the shaft.
4. In laser alignment, what does the term ‘Soft Foot’ refer to?
A. A flexible mounting pad
B. A condition where the machine feet do not evenly contact the baseplate
C. The use of rubber shims
D. Excessive vibration in the motor base
Answer: B
, Conceptual Explanation: Soft foot occurs when one or more feet of a machine do not sit
flat on the baseplate, causing frame distortion when bolts are tightened.
5. Which valve type is most suitable for throttling flow in a high-pressure system?
A. Globe valve
B. Gate valve
C. Check valve
D. Butterfly valve
Answer: A
Conceptual Explanation: Globe valves are specifically designed for regulating flow
(throttling), whereas gate valves are intended for fully open or closed service.
6. What is the purpose of a wear ring in a centrifugal pump?
A. To support the weight of the impeller
B. To reduce internal leakage from discharge to suction
C. To prevent shaft deflection
D. To balance the axial thrust
Answer: B
Conceptual Explanation: Wear rings provide a small, replaceable clearance between the
impeller and the casing to minimize internal recirculation leakage.
GRADE EXAM 2026/2027 QUESTIONS
AND VERIFIED ANSWERS
1. What is the primary cause of cavitation in a centrifugal pump?
A. Suction pressure dropping below the liquid’s vapor pressure
B. High discharge pressure
C. Excessive pump speed
D. Misalignment of the pump and motor
Answer: A
Conceptual Explanation: Cavitation occurs when the local pressure at the impeller eye
drops below the vapor pressure of the liquid, causing bubbles to form and then collapse
violently.
2. According to Pump Affinity Laws, how does the required horsepower change if the pump
speed is doubled?
A. It increases by eight times
B. It increases by four times
C. It doubles
D. It remains the same
,Answer: A
Conceptual Explanation: Horsepower varies with the cube of the speed change (2 to the
power of 3 = 8).
3. Which type of bearing is specifically designed to handle axial loads only?
A. Radial ball bearing
B. Thrust bearing
C. Needle bearing
D. Tapered roller bearing
Answer: B
Conceptual Explanation: Thrust bearings are designed to support loads that act parallel
to the axis of the shaft.
4. In laser alignment, what does the term ‘Soft Foot’ refer to?
A. A flexible mounting pad
B. A condition where the machine feet do not evenly contact the baseplate
C. The use of rubber shims
D. Excessive vibration in the motor base
Answer: B
, Conceptual Explanation: Soft foot occurs when one or more feet of a machine do not sit
flat on the baseplate, causing frame distortion when bolts are tightened.
5. Which valve type is most suitable for throttling flow in a high-pressure system?
A. Globe valve
B. Gate valve
C. Check valve
D. Butterfly valve
Answer: A
Conceptual Explanation: Globe valves are specifically designed for regulating flow
(throttling), whereas gate valves are intended for fully open or closed service.
6. What is the purpose of a wear ring in a centrifugal pump?
A. To support the weight of the impeller
B. To reduce internal leakage from discharge to suction
C. To prevent shaft deflection
D. To balance the axial thrust
Answer: B
Conceptual Explanation: Wear rings provide a small, replaceable clearance between the
impeller and the casing to minimize internal recirculation leakage.
