Mechanical Engineering - MCQ Practice Questions

In a welded joint, which type of stress is primarily responsible for failure in a butt weld under tensile loading?

A cast iron machine bed is subjected to fluctuating loads. Which material property is MOST important for its long-term reliability?

In journal bearing design, if the bearing length is doubled while keeping other parameters constant, how does the load capacity change?

A gear pair is designed with a contact ratio of 1.4. What does this indicate about the gear mesh?

Which of the following is the primary function of a Woodruff key in shaft design?

A coupling is required for a motor-pump assembly where slight misalignment and vibration are expected. Which coupling type is MOST suitable?

In the design of a flat belt drive, what is the primary criterion for determining the belt width?

A ball bearing with dynamic load rating C = 8000 N is subjected to a radial load of 2000 N. What is the approximate L10 life in millions of revolutions?

In spring design, what is the primary effect of shot peening on the fatigue strength of a spring?

A V-belt drive shows signs of slipping. Which of the following is NOT a likely cause?

In a brake design, which material property is MOST critical for brake pad selection?

A bolted joint is subject to a tensile load of 50 kN. If the bolt diameter is 16 mm and material is Grade 8.8, what is the safety factor? (Assume tensile strength = 640 MPa)

In helical gear design, why is the helix angle typically limited to less than 45 degrees?

A rotating shaft experiences combined bending and torsional stresses. Which failure theory is MOST appropriate for ductile materials?

In clutch design, what is the primary advantage of a multi-plate clutch over a single-plate clutch?

A simple epicyclic gear train is used in an automobile differential. What is its primary function?

In a hydrodynamic bearing, which of the following best describes the wedge film condition?

For a long slender column subjected to axial compression, buckling occurs when the load reaches the critical value. Which parameter has the MOST significant influence on critical load?

A tapered roller bearing is subjected to combined radial and thrust loads. How should the equivalent bearing load be calculated?

In a cam-follower system, which type of follower motion profile minimizes shock and vibration?