4851. The diameter of the nozzle (d) for maximum transmission of power is given by (where D = Diameter of pipe, f = Darcy ‘s coefficient of friction for pipe, and l = Length of pipe )
✅ 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.
4852. The toughness of a material __________ when it is heated.
increases
decreases
does not change
✅ The correct answer is option B.
4853. The co-efficient of rolling resistance for a truck weighing 63 500 N is 0.018. The rolling resistance to the truck is
1.143 N
11.43 N
114.3 N
1143 N
✅ The correct answer is option D.
4854. An aftercooler is used to
remove impurities from air
reduce volume of air
cause moisture and oil vapour to drop out
cool the air
✅ The correct answer is option C.
4855. The ability of a material to absorb energy in the plastic range is called
resilience
creep
fatigue strength
toughness
✅ The correct answer is option D.
4856. When the axes of the shafts, over which the gears are mounted, move relative to a fixed axis, then the train is known as reverted gear train.
Right
Wrong
✅ The correct answer is option B.
4857. The power of a boiler may be defined as
the ratio of heat actually used in producing the steam to the heat liberated in the furnace
the amount of water evaporated or steam produced in kg per kg of fuel burnt
the amount of water evaporated from and at 100° C into dry and saturated steam
the evaporation of 15.653 kg of water per hour from and at 100° C
✅ The correct answer is option B.
4858. The ball bearings are provided with a cage
to reduce friction
to facilitate slipping of balls
to prevent the lubricant from flowing out
to maintain the balls at a fixed distance apart
✅ The correct answer is option D.
4859. The value of gas constant (R) in S. I. units is
0.287 J/kgK
2.87 J/kgK
28.7 J/kgK
287 J/kgK
✅ The correct answer is option D.
4860. An ideal fluid is frictionless and incompressible.
Correct
Incorrect
✅ The correct answer is option A.