Mechanical Aptitude Mechanical Aptitude Ultimate 5 — Questions and Answers
Question 1: Which class of fit describes two mating parts where the shaft is always smaller than the hole, guaranteeing clearance for easy assembly?
- Clearance fit (Correct answer)
- Interference fit
- Transition fit
- Running fit
Correct answer: Clearance fit
A clearance fit ensures the shaft is always smaller than the hole across all tolerance conditions, allowing easy sliding or rotation.
Question 2: What does a manometer measure?
- Fluid pressure by the height of a liquid column (Correct answer)
- Fluid flow rate through a pipe
- The rotational speed of a shaft
- Temperature of a gas
Correct answer: Fluid pressure by the height of a liquid column
A manometer measures pressure by balancing it against the weight of a liquid column, with height proportional to pressure.
Question 3: A ramp (inclined plane) is 10 feet long and 2 feet high. What is the mechanical advantage?
- 5 (Correct answer)
- 2
- 10
- 0.2
Correct answer: 5
Mechanical advantage of an inclined plane = length / height = 10/2 = 5, meaning you apply 1/5 the force over 5× the distance.
Question 4: Which property of a material describes its ability to be drawn into wire without breaking?
- Ductility (Correct answer)
- Malleability
- Brittleness
- Hardness
Correct answer: Ductility
Ductility is the ability to deform under tensile stress without fracturing, which is required to draw a material into wire.
Question 5: In a planetary gear system, if the ring gear is fixed and the sun gear is the input, which component is the output?
- Planet carrier (Correct answer)
- Ring gear
- Sun gear
- Idler gear
Correct answer: Planet carrier
With the ring gear held stationary and the sun gear driven, the planet gears walk around inside the ring gear, carrying their carrier as the output.
Question 6: A pump moves 5 gallons per minute against a pressure of 120 PSI. Which change would most increase the system's flow rate without changing the pump?
- Increase the pipe diameter (Correct answer)
- Decrease the pipe diameter
- Add more bends to the piping
- Raise the discharge elevation
Correct answer: Increase the pipe diameter
Larger pipe diameter reduces friction losses (head loss), lowering system resistance and allowing more flow at the same pump output.
Question 7: What is the primary purpose of a thrust bearing?
- To support axial (longitudinal) loads along the shaft axis (Correct answer)
- To support radial loads perpendicular to the shaft
- To reduce shaft vibration
- To align two misaligned shafts
Correct answer: To support axial (longitudinal) loads along the shaft axis
Thrust bearings are designed specifically to resist forces acting parallel to the shaft axis (axial loads), preventing the shaft from sliding forward or backward.
Mechanical Aptitude Mechanical Aptitude Ultimate 5
Which class of fit describes two mating parts where the shaft is always smaller than the hole, guaranteeing clearance for easy assembly?