4661. The pre-ignition occurs before the spark is produced whereas detonation develops after the introduction of spark.
Agree
Disagree
✅ The correct answer is option A.
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.
4662. The hardness of steel increases if it contains
pearlite
ferrite
cementite
martensite
✅ The correct answer is option C.
4663. The fire tubes in a Cochran boiler are
horizontal
vertical
inclined
✅ The correct answer is option A.
4664. The function of an alternator in an automobile is to
supply electric power
convert mechanical energy into electrical energy
continually recharge the battery
partly convert engine power into electric power
✅ The correct answer is option C.
4665. Two shafts ‘A’ and ‘B’ transmit the same power. The speed of shaft ‘A’ is 250 r.p.m. and that of shaft ‘B’ is 300 r.p.m. The shaft ‘B’ has the greater diameter.
TRUE
FALSE
✅ The correct answer is option B.
4666. The function of a flywheel is
to convert reciprocating motion of the piston into rotary motion.
to convert rotary motion of the crankshaft into to and fro motion of the valve rod
to prevent fluctuation of speed
to keep the engine speed uniform at all load conditions
✅ The correct answer is option C.
4667. The relative humidity is defined as
the mass of water vapour present in 1 m3 of dry air
the mass of water vapour present in 1 kg of dry air
the ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure.
the ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure
✅ The correct answer is option D.
4668. Probabilistic time for completion of any activity can be found out from
optimistic time
pessimistic time
most likely time
all of these
✅ The correct answer is option D.
4669. The resistance to fatigue of a material is measured by
elastic limit
Young’s modulus
ultimate tensile strength
endurance limit
✅ The correct answer is option D.
4670. The gear train usually employed in clocks is a
simple gear train
reverted gear train
sun and planet gear
differential gear
✅ The correct answer is option B.