MCQ 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 MCQ Questions and Answers flashcards as text
What type of stress occurs when a material is pulled apart?
Answer: Tensile stress
Tensile stress occurs when forces act to stretch or pull apart a material. It is calculated as force per unit area (σ = F/A) and is the opposite of compressive stress, which pushes material together.
What is the primary purpose of a differential in a vehicle?
Answer: To allow wheels to rotate at different speeds during turns
A differential allows the outer wheel to rotate faster than the inner wheel during turns, preventing tire scrubbing and maintaining traction. Without a differential, both drive wheels would be forced to turn at the same speed, causing handling problems in curves.
Which type of thread has a V-shaped profile and is most common for fasteners?
Answer: Metric/Unified thread
Metric (ISO) and Unified (UNC/UNF) threads have a 60° V-shaped profile and are the most common thread types for nuts, bolts, and screws. Square and Acme threads are used for power transmission, and buttress threads resist force in one direction.
What does a thermostat do in a cooling system?
Answer: Regulates coolant flow based on temperature
A thermostat is a temperature-sensitive valve that regulates coolant flow through the cooling system. It remains closed when the engine is cold (allowing faster warm-up) and opens progressively as temperature rises to allow coolant to flow through the radiator.
What mechanical advantage does a screw provide?
Answer: Conversion of rotational force into large linear force
A screw converts rotational motion into linear motion with high mechanical advantage. The closer together the threads (finer pitch), the greater the mechanical advantage — a small input torque generates a very large linear pushing or pulling force.
What is the purpose of a keyway in a shaft?
Answer: To prevent relative rotation between the shaft and a mounted component
A keyway is a machined slot in a shaft (and matching slot in the hub of a gear, pulley, or coupling) that holds a key — a small metal piece that locks the two components together, preventing relative rotation while transmitting torque.