2121. Gears can be best produced on mass production by
shaping
casting
forming
hobbing
✅ The correct answer is option D.
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.
2122. The maximum shear stress theory is used for
brittle materials
ductile materials
plastic materials
non-ferrous materials
✅ The correct answer is option B.
2123. Which of the following would lead to a reduction in thermal resistance?
In conduction, reduction in the thickness of the material and an increase in thermal conductivity.
In convection, stirring of the fluid and cleaning the heating surface.
In radiation, increasing the temperature and reducing the emissivity.
all of the above
✅ The correct answer is option D.
2124. A tapered key which fits in a key way in the hub and is flat on the shaft, is known as
feather key
gib-head key
wood ruff key
flat saddle key
✅ The correct answer is option D.
2125. Two shafts of the same length and material are joined in series. If the ratio of their diameters is 2, then the ratio of their angles of twist will be
2
4
8
16
✅ The correct answer is option D.
2126. Which of the following formula is used in designing a connecting rod ?
Euler’s formula
Rankine’s formula
Johnson’s straight line formula
Johnson’s parabolic fo
✅ The correct answer is option B.
2127. The cooling system used for supersonic aircrafts and rockets is
simple air cooling system
boot-strap air cooling system
reduced ambient air cooling system
regenerative air cooli
✅ The correct answer is option D.
2128. A refrigerating system operating on reversed Brayton refrigeration cycle is used for maintaining 250 K. If the temperature at the end of constant pressure cooling is 300 K and rise in the temperature of air in the refrigerator is 50 K, then the net work of compression will be (assume air as working substance with cp = 1 kJ/kg)
25 kJ/kg
50 kJ/kg
l00 kJ/kg
125 kJ/kg
✅ The correct answer is option B.
2129. A Pelton wheel develops 1750 kW under a head of 100 metres while running at 200 r.p.m. and discharging 2500 litres of water per second. The unit discharge of wheel is
0.25 m3/s
0.5 m3/s
1.5 m3/s
2.5 m3/s
✅ The correct answer is option A.
2130. Which of the following property of the instantaneous centre is correct ?
A rigid link rotates instantaneously relative to another link at the instantaneous centre for the configuration of the mechanism considered.
The two rigid links have no linear velocity relative to each other at the instantaneous centre.
The velocity of the instantaneous centre relative to any third rigid link is same whether the instantaneous centre is regarded as a point on the first rigid link or on the second rigid link.
all of the above
✅ The correct answer is option D.