4121. A Pelton wheel working under a constant head and discharge, has maximum efficiency when the speed ratio is
0.26
0.36
0, 46
0.56
✅ The correct answer is option C.
Mechanical Engineering
Prepare with the best Mechanical Engineering MCQs with answers and explanations for exams, interviews, and job tests. Our collection covers core topics such as engineering mechanics, thermodynamics, strength of materials, theory of machines, fluid mechanics, heat transfer, manufacturing processes, machine design, and power plant engineering. These Mechanical Engineering multiple-choice questions are designed for students, fresh graduates, and professionals preparing for NTS, PPSC, FPSC, PEC exams, GATE, university entry tests, and recruitment assessments. Strengthen your technical knowledge and problem-solving ability with our updated and comprehensive Mechanical Engineering MCQs.
4122. The cracks in helical springs used in railway carriages usually start on the inner side of the coil because of the fact that
it is subjected to a higher stress than the outer side
it is subjected to a higher cyclic loading than the outer side
it is more stretched than the outer side during the manufacturing process
it has a lower curvatu
✅ The correct answer is option B.
4124. The direction of linear velocity of any point on a link with respect to another point on the same link is
parallel to the link joining the points
perpendicular to the link joining the points
at 45° to the link joining the points
none of the above
✅ The correct answer is option B.
4125. The efficiency of Diesel cycle depends upon
temperature limits
pressure ratio
compression ratio
cut-off ratio and comp
✅ The correct answer is option D.
4126. The ratio of the inertia force to the surface tension force is called Weber’s number.
Correct
Incorrect
✅ The correct answer is option A.
4127. The boiling point of carbon dioxide is
-20.5°C
-50°C
-63.3°C
-78.3°C
✅ The correct answer is option D.
4128. Effort of a governor is the
mean force exerted at the sleeve for a given percentage change of speed
workdone at the sleeve for maximum equilibrium speed
mean force exerted at the sleeve for maximum equilibrium speed
none of the above
✅ The correct answer is option A.
4129. The __________ engines can work on very lean mixture of fuel.
spark ignition
compression ignition
✅ The correct answer is option B.
4130. The abrasive slurry used in ultra-sonic machining contains fine particles of
aluminium oxide
boron carbide
silicon carbide
any one of these
✅ The correct answer is option D.