EEI TECH EEI Tech Mechanical Concept 3 — Questions and Answers
Question 1: A first-class lever has the effort 4 ft from the fulcrum and the load 1 ft from the fulcrum. What is its mechanical advantage?
- 4 (Correct answer)
- 1
- 0.25
- 5
Correct answer: 4
Mechanical advantage equals effort arm divided by load arm: 4/1 = 4.
Question 2: Which gear arrangement allows a driver and driven shaft to rotate in the SAME direction using gears alone?
- Two gears with an idler gear between them (Correct answer)
- Two directly meshed gears
- A single gear
- A worm gear pair
Correct answer: Two gears with an idler gear between them
An idler gear placed between two gears reverses direction twice, keeping driver and driven turning the same way.
Question 3: On a screw, the distance the screw advances in one full turn is called the:
- Pitch (Correct answer)
- Diameter
- Torque
- Thread angle
Correct answer: Pitch
Pitch is the linear distance traveled per complete revolution of the screw.
Question 4: A 200 lb load sits on a frictionless inclined plane 10 ft long with a vertical rise of 2 ft. What is the ideal mechanical advantage?
- 5 (Correct answer)
- 2
- 10
- 0.2
Correct answer: 5
Ideal mechanical advantage equals length divided by height: 10/2 = 5.
Question 5: Which of the following best describes torque?
- A rotational force that tends to cause rotation (Correct answer)
- A pulling force in a straight line
- The speed of a rotating shaft
- The weight of an object
Correct answer: A rotational force that tends to cause rotation
Torque is the turning effect produced by a force acting at a distance from a pivot.
Question 6: Water flows through a pipe that narrows from a wide section to a narrow section. In the narrow section the water:
- Flows faster (Correct answer)
- Flows slower
- Stops flowing
- Changes direction
Correct answer: Flows faster
By continuity, the same volume must pass through a smaller area, so velocity increases.
Question 7: A flywheel is used in machines primarily to:
- Store rotational energy and smooth out speed variations (Correct answer)
- Increase friction
- Reduce the weight of the machine
- Generate electricity directly
Correct answer: Store rotational energy and smooth out speed variations
A flywheel's inertia stores energy and keeps rotational speed steady between power strokes.
EEI TECH EEI Tech Mechanical Concept 3
A first-class lever has the effort 4 ft from the fulcrum and the load 1 ft from the fulcrum.
What is its mechanical advantage?