Texas Civil Service Exam Mechanical and Spatial Aptitude 5 — Questions and Answers
Question 1: A technician needs to join two metal pipes end-to-end so the connection can be disassembled for maintenance. The best method is:
- Welding
- Riveting
- Threaded coupling (Correct answer)
- Brazing
Correct answer: Threaded coupling
Threaded couplings allow pipes to be connected and disconnected repeatedly without damaging the pipe, making maintenance easy.
Question 2: An L-shaped object is rotated 90° clockwise in your mind. If the long arm initially pointed up and the short arm pointed right, after rotation the long arm points:
- Left
- Right (Correct answer)
- Down
- Up
Correct answer: Right
Rotating 90° clockwise moves up→right, right→down, so the long arm (originally pointing up) now points right.
Question 3: A pump moves fluid against gravity up a 20-foot pipe. Which factor most directly determines how much power the pump needs?
- The color of the fluid
- The weight of fluid moved per unit time (Correct answer)
- The temperature of the fluid
- The material of the pipe
Correct answer: The weight of fluid moved per unit time
Pump power required = weight flow rate × head (height), so moving heavier fluid or more fluid per minute requires more power.
Question 4: Which of the following is NOT a type of bearing used to reduce friction in rotating machinery?
- Ball bearing
- Roller bearing
- Thrust bearing
- Tension bearing (Correct answer)
Correct answer: Tension bearing
Ball, roller, and thrust bearings are all standard bearing types; 'tension bearing' is not a standard classification.
Question 5: A piece of sheet metal is shown flat with a fold line marked. After folding up 90° along the line, a notch that was on the fold line will appear:
- On the top face only
- On the vertical face only
- Split between the top and vertical faces (Correct answer)
- Eliminated by the fold
Correct answer: Split between the top and vertical faces
A feature on the fold line will be split between both surfaces that meet at that fold, appearing on both faces after bending.
Question 6: A circuit has two resistors in parallel: one 4-ohm and one 12-ohm resistor. What is the total resistance?
- 16 ohms
- 8 ohms
- 4 ohms
- 3 ohms (Correct answer)
Correct answer: 3 ohms
Parallel resistance: 1/R = 1/4 + 1/12 = 3/12 + 1/12 = 4/12, so R = 12/4 = 3 ohms.
Question 7: A centrifugal pump is running but delivers less flow than expected. Which condition is the LEAST likely cause?
- Partially clogged inlet strainer
- Air leak on the suction side
- Impeller worn or damaged
- Discharge pipe painted a dark color (Correct answer)
Correct answer: Discharge pipe painted a dark color
Pipe color has no effect on pump flow; clogged inlets, air leaks, and worn impellers all directly reduce pump output.
Texas Civil Service Exam Mechanical and Spatial Aptitude 5
A technician needs to join two metal pipes end-to-end so the connection can be disassembled for maintenance.
The best method is: