The main cause for the irreversibility is
Mechanical and fluid friction
Unrestricted expansion
Heat transfer with a finite temperature difference
All of the above
Correct Answer :
D. All of the above
Related Questions
The amount of heat required to raise the temperature of 1 kg of water through one Kelvin is called
Specific heat at constant volume
Specific heat at constant pressure
kilo-Joule
None of these
A column of length (l) with both ends fixed may be considered as equivalent to a column of length __________ with both ends hinged.
l/8
l/4
l/2
l
A simply supported beam with a gradually varying load from zero at B and w per unit length at A is shown in the below figure. The shear force at B is equal to
wl/6
wl/3
wl
2wl/3
In a uniform bar, supported at one end in position, the maximum stress under self weight of bar shall occur at the
Middle of bar
Supported end
Bottom end
None of these
Percentage reduction of area in performing tensile test on cast iron may be of the order of
50 %
25 %
0 %
15 %
In the torsion equation T/J = τ/r = Gθ/ L, the term J/R is called
Shear modulus
Section modulus
Polar modulus
None of these
The capacity of a strained body for doing work on the removal of the straining force, is called
Strain energy
Resilience
Proof resilience
Impact energy
A boiler shell 200 cm diameter and plate thickness 1.5 cm is subjected to internal pressure of 1.5 MN/m, and then the hoop stress will be
30 MN/m²
50 MN/m²
100 MN/m²
200 MN/m²
When a thin cylindrical shell is subjected to an internal pressure, the volumetric strain is (where ε₁ = Hoop strain, and ε₂ = Longitudinal strain)
2ε₁ - ε₂
2ε₁ + ε₂
2ε₂ - ε₁
2ε₂ + ε₁
The value of cp/cv for air is
1
1.4
1.45
2.3
When a rectangular beam is loaded transversely, the maximum compressive stress is developed on the
Top layer
Bottom layer
Neutral axis
Every cross-section
A thin cylindrical shell of diameter (D) and thickness (t) is subjected to an internal pressure (p). The ratio of longitudinal strain to volumetric strain is
(m - 1)/ (2m - 1)
(2m - 1)/ (m - 1)
(m - 2)/ (3m - 4)
(m - 2)/ (5m - 4)
When coal is first dried and then crushed to a fine powder by pulverising machine, the resulting fuel is called
Wood charcoal
Bituminous coal
Briquetted coal
None of these
When shear force at a point is zero, then bending moment is _________ at that point.
Zero
Minimum
Maximum
Infinity
The process is adiabatic, if the value of n in the equation pvn = C, is
0
1
γ
∝
When both ends of a column are fixed, the effective length is
Its own length
Twice its length
Half its length
1/√2 × its length
Otto cycle consists of following four processes
Two isothermals and two isentropic
Two isentropic and two constant volumes
Two isentropic, one constant volume and one constant pressure
Two isentropic and two constant pressures
Which of the following is correct?
Gauge pressure = Absolute pressure + Atmospheric pressure
Absolute pressure = Gauge pressure + Atmospheric pressure
Absolute pressure = Gauge pressure - Atmospheric pressure
Atmospheric pressure = Absolute pressure + Gauge pressure
The property of a working substance which increases or decreases as the heat is supplied or removed in a reversible manner, is known as
Enthalpy
Internal energy
Entropy
External energy
The measurement of a thermodynamic property known as temperature is based on
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
None of these
According to Kelvin-Planck's statement, a perpetual motion of the __________ is impossible.
First kind
Second kind
Third kind
None of these
The thickness of a thin cylindrical shell with hemispherical ends is __________ that of spherical ends.
Equal to
More than
Less than
None of these
Carbonisation of coal consists of
Drying and crushing the coal to a fine powder
Moulding the finely ground coal under pressure with or without a binding material
Heating the wood with a limited supply of air to temperature not less than 280°C
None of the above
Which of the following statement is wrong?
The closed cycle gas turbine plants are external combustion plants.
In the closed cycle gas turbine, the pressure range depends upon the atmospheric pressure.
The advantage of efficient internal combustion is eliminated as the closed cycle has an external surface.
In open cycle gas turbine, atmosphere acts as a sink and no coolant is required.
Select the wrong statement
A Joule cycle consists of two constant volume and two isentropic processes.
An Otto cycle consists of two constant volume and two isentropic processes.
An Ericsson cycle consists of two constant pressure and two isothermal processes.
All of the above
Reversed joule cycle is called
Carnot cycle
Rankine cycle
Brayton cycle
Bell Coleman cycle
Diesel cycle consists of __________ processes.
Two constant volume and two isentropic
Two constant pressure and two isentropic
Two constant volume and two isothermal
One constant pressure, one constant volume and two isentropic
Euler's formula holds good only for
Short columns
Long columns
Both short and long columns
Weak columns
The maximum shear stress, in the given figure, is equal to __________ of the Mohr's circle.
Radius
Diameter
Circumference
Area
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