M C Q s D r i v e

Mechanical Engineering Mcqs 1919 MCQs [All-Courses]

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Mechanical Engineering MCQs prepared for job test and interview preparation, especially for fresh graduates, students, and candidates appearing in competitive exams. These multiple-choice questions cover key topics such as Machine Design, Theory of Machines, Hydraulic Machines, and other important mechanical engineering concepts.

Moisture would find its way into insulation by vapour pressure unless it is prevented by __________________ ?
A high thickness of insulation
B high vapour pressure
C less thermal conductivity insulator
D a vapour seal
Correct Answer: a vapour seal
Heat transfer by radiation mainly depends upon___________________?
A its temperature
B nature of the body
C kind and extent of its surface
D all of the above
Correct Answer: all of the above
Which of the following has maximum value of thermal conductivity________________?
A aluminium
B steel
C brass
D copper
Correct Answer: aluminium
Heat flows from one body to other when they have_________________?
A different heat contents
B different specific heat
C different atomic structure
D different temperatures
Correct Answer: different temperatures
According to Prevost theory of heat exchange ___________________?
A it is impossible to transfer heat from low temperature source to t high temperature source
B heat transfer by radiation requires no medium
C all bodies above absolute zero emit radiation
D heat transfer in most of the cases takes place by combination of conduction, convection and radiation
Correct Answer: all bodies above absolute zero emit radiation
Thermal diffusivity of a substance is ____________________?
A proportional of thermal conductivity
B inversely proportional to k
C proportional to (k)
D inversely proportional to k2
Correct Answer: proportional of thermal conductivity
The ratio of heat flow Q1/Q2 from two walls of same thickness having their thermal conductivities as ATj – 2K2 will be ________________?
A I
B 0.5
C 2
D 0.25
Correct Answer: 2
Thermal conductivity of a material may be defined as the________________?
A quantity of heat flowing in one second through one cm cube of material when opposite faces ^re maintained at a temperature difference of 1°C
B quantity of heat flowing in one second through a slab of the material of area one cm square, thickness 1 cm when its faces differ in temperature by 1°C
C heat conducted in unit time across unit area through unit thickness when a temperature difference of unity is maintained between opposite faces
D all of the above
Correct Answer: all of the above
Which of the following is expected to have highest thermal conductivity_______________?
A steam
B solid ice
C melting ice
D water
Correct Answer: solid ice
In heat transfer, conductance equals conductivity (kcal/hr/sqm/°C/cm) divided by ________________?
A hr (time)
B sqm (area)
C °C (temperature)
D cm (thickness)
Correct Answer: cm (thickness)