Mechanical Aptitude FREE Mechanical Aptitude Ultimate Question and Answers 3 — Questions and Answers
Question 1: A wheelbarrow is an example of which class of lever?
- Second-class lever (Correct answer)
- First-class lever
- Third-class lever
- It is not a lever
Correct answer: Second-class lever
A wheelbarrow places the load between the fulcrum (wheel) and the effort (handles), which defines a second-class lever.
Question 2: Two meshing gears have 15 and 45 teeth respectively. If the smaller gear rotates at 900 RPM, how fast does the larger gear rotate?
- 300 RPM (Correct answer)
- 900 RPM
- 2,700 RPM
- 450 RPM
Correct answer: 300 RPM
Gear speed is inversely proportional to the number of teeth, so the larger gear turns at 900 × (15/45) = 300 RPM.
Question 3: A pipe with a 1-inch diameter narrows to a 0.5-inch diameter. According to the continuity principle, what happens to the fluid velocity in the narrower section?
- It increases by a factor of 4 (Correct answer)
- It doubles
- It stays the same
- It decreases by half
Correct answer: It increases by a factor of 4
Flow rate is constant, and since area is proportional to the square of diameter, halving the diameter reduces area by a factor of 4, so velocity increases by a factor of 4.
Question 4: Which of the following materials would be the best conductor of heat?
- Copper (Correct answer)
- Wood
- Rubber
- Concrete
Correct answer: Copper
Copper has one of the highest thermal conductivities of common materials, making it an excellent heat conductor.
Question 5: A screw has 8 threads per inch. What is the mechanical advantage if the screwdriver handle has a circumference of 4 inches?
- 32 (Correct answer)
- 8
- 4
- 16
Correct answer: 32
The mechanical advantage of a screw equals the handle circumference divided by the pitch; with 8 threads per inch the pitch is 1/8 inch, so MA = 4 ÷ (1/8) = 32.
Question 6: An object is placed on a ramp inclined at 30 degrees. Ignoring friction, what fraction of the object's weight acts as a force pulling it down the ramp?
- One-half (Correct answer)
- One-quarter
- Three-quarters
- The full weight
Correct answer: One-half
The component of gravitational force along a 30-degree incline is weight × sin(30°), and sin(30°) = 0.5, so half the weight pulls the object down the ramp.
Mechanical Aptitude FREE Mechanical Aptitude Ultimate Question and Answers 3
A wheelbarrow is an example of which class of lever?