Knowledge Questions and Answers Flashcards
6 cards from real MECHANICAL APTITUDE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Knowledge Questions and Answers flashcards as text
What is the function of a governor in a mechanical system?
Answer: To automatically regulate speed
A governor automatically regulates the speed of a machine, typically an engine or turbine, by adjusting fuel supply or load in response to speed changes. It maintains a desired operating speed despite varying loads.
What is the difference between ferrous and non-ferrous metals?
Answer: Ferrous metals contain iron, non-ferrous do not
Ferrous metals contain iron as their primary component (steel, cast iron, wrought iron), while non-ferrous metals do not contain significant iron (aluminum, copper, brass, titanium). Ferrous metals are typically magnetic and susceptible to rust.
What mechanical principle explains why longer wrenches require less effort to turn a bolt?
Answer: Mechanical advantage through leverage
A longer wrench provides greater mechanical advantage because torque equals force multiplied by the perpendicular distance from the pivot (T = F × d). Increasing the wrench length increases the moment arm, so less force is needed to produce the same torque.
What is the purpose of tempering steel after it has been hardened?
Answer: To reduce brittleness while maintaining hardness
Tempering is a heat treatment performed after hardening that reduces brittleness while retaining much of the hardness. Hardened steel is extremely hard but brittle; tempering heats it to a moderate temperature to relieve internal stresses and achieve a balance of hardness and toughness.
In a belt-and-pulley system, what happens if the driven pulley is larger than the driving pulley?
Answer: The driven pulley rotates slower with more torque
When the driven pulley is larger than the driving pulley, the driven pulley rotates slower but with greater torque. The speed ratio is inversely proportional to the diameter ratio, providing a speed reduction and torque multiplication.
What does the term 'tolerance' mean in mechanical engineering?
Answer: The allowable variation in a dimension
Tolerance is the permissible range of variation in a physical dimension. No manufacturing process produces parts with perfect dimensions, so tolerances specify the acceptable upper and lower limits for a dimension to ensure proper fit and function.