A process, in which the working substance neither receives nor gives out heat to its surroundings during its expansion or compression, is called
Isothermal process
Hyperbolic process
Adiabatic process
Polytropic process
Correct Answer :
C. Adiabatic process
Related Questions
The efficiency of Diesel cycle with decrease in cut-off
Increases
Decreases
First increases and then decreases
First decreases and then increases
A riveted joint in which the number otrivets decrease from innermost to outer most rows is called
Chain riveted joint
Diamond riveted joint
Crisscross riveted joint
Zigzag riveted joint
Which of the following has the highest calorific value?
Peat
Lignite
Bituminous coal
Anthracite coal
The maximum bending moment for the beam shown in the below figure, is
wl²/3√3
wl²/6√3
wl²/9√3
wl²/12√3
The stress induced in a body, when suddenly loaded, is ________ the stress induced when the same load is applied gradually.
Equal to
One-half
Twice
Four times
One kg of carbon monoxide requires __________ kg of oxygen to produce 11/7 kg of carbon dioxide gas.
4/7
11/4
9/7
All of these
The volumetric or molar specific heat at constant pressure is the product of
Molecular mass of the gas and the specific heat at constant volume
Atomic mass of the gas and the gas constant
Molecular mass of the gas and the gas constant
None of the above
Which is the false statement about true stress strain method?
It does not exist
It is more sensitive to changes in both metallurgical and mechanical conditions
It gives a more accurate picture of the ductility
It can be correlated with stress strain values in other tests like torsion, impact, combined stress tests etc.
If the depth is kept constant for a beam of uniform strength, then its width will vary in proportional to
Bending moment (i.e. M)
Bending moment² (i.e. M²)
Bending moment³ (i.e. M³)
Bending moment⁴ (i.e. M⁴)
In an irreversible process, there is a
Loss of heat
No loss of heat
Gain of heat
No gain of heat
The cycle in which heat is supplied at constant volume and rejected at constant pressure is known as
Dual combustion cycle
Diesel cycle
Atkinson cycle
Rankine cycle
The entropy may be expressed as a function of
Pressure and temperature
Temperature and volume
Heat and work
All of these
The relation between Young's modulus (E), shear modulus (C) and bulk modulus (K) is given by
E = 3K.C/(3K + C)
E = 6K.C/(3K + C)
E = 9K.C/(3K + C)
E = 12K.C/(3K + C)
The state of a substance whose evaporation from its liquid state is complete, is known as
Vapour
Perfect gas
Air
Steam
Energy can neither be created nor destroyed, but it can be transformed from one form to another. This statement is known as
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
Kinetic theory of gases
The ideal efficiency of a Brayton cycle with regeneration, with increase in pressure ratio will
Increase
Decrease
Remain unchanged
Increase/decrease depending on application
For the same compression ratio, the efficiency of dual combustion cycle is
Greater than Diesel cycle and less than Otto cycle
Less than Diesel cycle and greater than Otto cycle
Greater than Diesel cycle
Less than Diesel cycle
The thickness of a thin cylindrical shell with hemispherical ends is __________ that of spherical ends.
Equal to
More than
Less than
None of these
The strain energy stored in a solid circular shaft subjected to shear stress (τ), is: (Where G = Modulus of rigidity for the shaft material)
τ²/ 2G × Volume of shaft
τ/ 2G × Volume of shaft
τ²/ 4G × Volume of shaft
τ/ 4G × Volume of shaft
In an isothermal process,
There is no change in temperature
There is no change in enthalpy
There is no change in internal energy
All of these
A pressure vessel is said to be a thick shell, when
It is made of thick sheets
The internal pressure is very high
The ratio of wall thickness of the vessel to its diameter is less than 1/10.
The ratio of wall thickness of the vessel to its diameter is greater than 1/10.
Principal planes are planes having
Maximum shear stress
No shear stress
Minimum shear stress
None of the above
When a closely-coiled helical spring of mean diameter (D) is subjected to an axial load (W), the deflection of the spring (δ) is given by (where d = Diameter of spring wire, n = No. of turns of the spring, and C = Modulus of rigidity for the spring material)
WD3n/Cd⁴
2WD3n/Cd⁴
4WD3n/Cd⁴
8WD3n/Cd⁴
A masonry dam may fail due to
Tension in the masonry of the dam and its base
Overturning of the dam
Crushing of masonry at the base of the dam
Any one of the above
The work ratio of simple gas turbine cycle depends upon
Maximum cycle temperature
Minimum cycle temperature
Pressure ratio
All of these
The entropy __________ in an irreversible cyclic process.
Remains constant
Decreases
Increases
None of these
One reversible heat engine operates between 1600 K and T2 K and another reversible heat engine operates between T2 K and 400 K. If both the engines have the same heat input and output, then temperature T2 is equal to
800 K
1000 K
1200 K
1400 K
One kg of carbon monoxide requires _______kg of oxygen to produce 11/7 kg of carbon dioxide gas.
11/7
9/7
4/7
All of the above
When a body is subjected to a direct tensile stress (σ) in one plane, then maximum normal stress occurs at a section inclined at __________ to the normal of the section.
0°
30°
45°
90°
The general gas energy equation is (where Q1 - 2 = Heat supplied, dU = Change in internal energy, and W1 - 2 = Work done in heat units)
Q1 - 2 = dU + W1 - 2
Q1 - 2 = dU - W1 - 2
Q1 - 2 = dU/W1 - 2
Q1 - 2 = dU × W1 - 2