Texas Civil Service Exam Mechanical and Spatial Aptitude 4 — Questions and Answers
Question 1: A block is shown in a 3D drawing with a hole drilled straight through from front to back. In a top-view drawing, the hole would appear as:
- A solid circle
- A dashed circle
- Two parallel dashed lines (Correct answer)
- Nothing
Correct answer: Two parallel dashed lines
Hidden features (not visible from the viewing direction) are shown as dashed lines; a front-to-back hole appears as two dashed lines in the top view.
Question 2: Which type of valve completely stops fluid flow when closed, offering low resistance to flow when open?
- Globe valve
- Needle valve
- Gate valve (Correct answer)
- Check valve
Correct answer: Gate valve
A gate valve uses a sliding gate to fully open or close flow with minimal restriction when fully open, unlike globe valves which restrict flow even when open.
Question 3: If a wheel with a 12-inch radius is attached to an axle with a 3-inch radius, what is the mechanical advantage?
- 2
- 3
- 4 (Correct answer)
- 6
Correct answer: 4
Mechanical advantage of a wheel and axle = wheel radius / axle radius = 12/3 = 4.
Question 4: A rectangular box is 4 inches long, 3 inches wide, and 2 inches tall. If viewed from directly above, what is the area of the shape you see?
- 6 sq inches
- 8 sq inches
- 12 sq inches (Correct answer)
- 24 sq inches
Correct answer: 12 sq inches
The top view shows the full length × width = 4 × 3 = 12 square inches.
Question 5: In a belt-and-pulley system, a small pulley drives a large pulley. Compared to the small pulley, the large pulley will:
- Rotate faster with more torque
- Rotate slower with more torque (Correct answer)
- Rotate faster with less torque
- Rotate slower with less torque
Correct answer: Rotate slower with more torque
A larger driven pulley rotates more slowly than the driver but produces greater torque, trading speed for force.
Question 6: A pipe carrying water develops a leak due to a crack along its length. Which type of stress most likely caused this crack?
- Compressive stress
- Shear stress
- Tensile (hoop) stress (Correct answer)
- Bending stress
Correct answer: Tensile (hoop) stress
Internal water pressure creates hoop (tensile) stress acting outward around the pipe's circumference, which can cause longitudinal cracks.
Question 7: When two objects of different temperatures touch, heat flows:
- From the cooler object to the warmer object
- From the warmer object to the cooler object (Correct answer)
- In both directions equally
- Only if the objects are metal
Correct answer: From the warmer object to the cooler object
Heat always flows from higher temperature to lower temperature until thermal equilibrium is reached.
Texas Civil Service Exam Mechanical and Spatial Aptitude 4
A block is shown in a 3D drawing with a hole drilled straight through from front to back.
In a top-view drawing, the hole would appear as: