Apprenticeship Exam Mechanical Aptitude and Principles 2 — Questions and Answers
Question 1: When two gears of equal size and equal tooth count are meshed together, the driven gear will:
- Rotate faster than the drive gear
- Rotate slower than the drive gear
- Rotate at the same speed as the drive gear (Correct answer)
- Not rotate until pressure builds up
Correct answer: Rotate at the same speed as the drive gear
Two meshing gears with equal tooth counts rotate at the same speed but in opposite directions.
Question 2: A compression spring has a spring constant of 50 lbs/inch and is compressed 2 inches from its natural length. What force is required?
- 50 lbs
- 100 lbs (Correct answer)
- 150 lbs
- 400 lbs
Correct answer: 100 lbs
Using Hooke's Law, force = spring constant × displacement: 50 lbs/inch × 2 inches = 100 lbs.
Question 3: Torque is best defined as:
- The speed of a rotating shaft measured in RPM
- A rotational force that causes or tends to cause rotation about an axis (Correct answer)
- The weight of a component measured during motion
- The friction generated between two rotating surfaces
Correct answer: A rotational force that causes or tends to cause rotation about an axis
Torque is a rotational force (moment) that causes an object to rotate around an axis, commonly measured in foot-pounds or Newton-meters.
Question 4: If you double the pressure in a pneumatic system while keeping the piston area the same, the output force will:
- Stay the same
- Be cut in half
- Double (Correct answer)
- Quadruple
Correct answer: Double
Since Force = Pressure × Area, doubling the pressure while area stays constant directly doubles the output force.
Question 5: Which type of friction acts between two surfaces that are moving (sliding) against each other?
- Static friction
- Rolling friction
- Kinetic friction (Correct answer)
- Fluid friction
Correct answer: Kinetic friction
Kinetic (sliding) friction is the resistive force acting between surfaces that are in relative motion against each other.
Question 6: A belt drive has a drive pulley of 4-inch diameter running at 900 RPM and a driven pulley of 12-inch diameter. What is the speed of the driven pulley?
- 100 RPM
- 300 RPM (Correct answer)
- 600 RPM
- 2700 RPM
Correct answer: 300 RPM
Belt speed is constant, so the driven pulley with 3× the diameter rotates at 1/3 the speed: 900 ÷ 3 = 300 RPM.
Question 7: The center of gravity of an object is best described as:
- Always at the exact geometric center of the object
- The point where the object's weight is balanced equally in all directions (Correct answer)
- The heaviest single point within the object
- Always located on the outer surface of the object
Correct answer: The point where the object's weight is balanced equally in all directions
The center of gravity is the point where the total weight of the object is considered to act, with mass distributed evenly in all directions from that point.
Apprenticeship Exam Mechanical Aptitude and Principles 2
When two gears of equal size and equal tooth count are meshed together, the driven gear will: