The following cycle is used for air craft refrigeration
Brayton cycle
Joule cycle
Carnot cycle
Reversed Brayton cycle
Correct Answer :
D. Reversed Brayton cycle
Related Questions
The efficiency of a gas turbine is given by
(Net work output)/(Workdone by the turbine)
(Net work output)/(Heat supplied)
(Actual temperature drop)/(Isentropic temperature drop)
(Isentropic increase in temperature)/(Actual increase in temperature)
The lower layer of the beam as shown in the below figure, will be
In tension
In compression
Neither in tension nor in compression
None of these
If the radius of wire stretched by a load is doubled, then its Youngs modulus will be
Doubled
Halved
Becomes four times
None of the above
Volumetric strain for a rectangular specimen of length l, breadth b and thickness t subjected to a pull of P is given by
e (1 - 2m)
e (1 - 2/m)
e (m - 2)
e (2/m - 1)
The rivets are used for __________ fastenings.
Permanent
Temporary
Semi-permanent
None of these
A tri-atomic molecule consists of __________ atoms.
One
Two
Three
Four
The assumption made in Euler's column theory is that
The failure of column occurs due to buckling alone
The length of column is very large as compared to its cross-sectional dimensions
The column material obeys Hooke's law
All of the above
The stress at which extension of the material takes place more quickly as compared to the increase in load is called
Elastic point of the material
Plastic point of the material
Breaking point of the material
Yielding point of the material
In a reversible adiabatic process, the ratio of T1/T2 is equal to
(p2/p1)γ - 1/ γ
(p1/p2)γ - 1/ γ
(v2/v1)γ - 1/ γ
(v1/v2)γ - 1/ γ
Producer gas is obtained by
Partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
Carbonisation of bituminous coal
Passing steam over incandescent coke
Passing air and a large amount of steam over waste coal at about 650°C
One molecule of oxygen consists of __________ atoms of oxygen.
2
4
8
16
The heat and mechanical energies are mutually convertible. This statement was established by
Boyle
Charles
Joule
None of these
During a tensile test on a specimen of 1 cm cross-section, maximum load observed was 8 tonnes and area of cross-section at neck was 0.5 cm². Ultimate tensile strength of specimen is
4 tonnes/ cm²
8 tonnes/ cm²
16 tonnes/ cm²
22 tonnes/ cm²
The state of stress at a point in a loaded member is shown in the below figure. The magnitude of maximum shear stress is
10 MPa
30 MPa
50 MPa
100 MPa
For the constant pressure and heat input, the air standard efficiency of gas power cycle is in the order
Dual cycle, Diesel cycle, Otto cycle
Otto cycle, Diesel cycle, Dual cycle
Dual cycle, Otto cycle, Diesel cycle
Diesel cycle, Otto cycle, Dual cycle
If Th is the torque resisting capacity of a hollow shaft and Ts is that of a solid shaft, of the same material, length and weight. Then,
Th > Ts
Th < Ts
Th = Ts
None of these
After reaching the yielding stage while testing a mild steel specimen, strain
Becomes constant
Starts decreasing
Increases without any increase in load
None of the above
Which of the following process can be made reversible with the help of a regenerator?
Constant pressure process
Constant volume process
Constant pvn process
All of these
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
The extremeties of any diameter on Mohr's circle represent
Principal stresses
Normal stresses on planes at 45°
Shear stresses on planes at 45°
Normal and shear stresses on a plane
The materials having same elastic properties in all directions are called
Ideal materials
Uniform materials
Isotropic materials
Piratical materials
Mond gas is obtained by
Partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
Carbonisation of bituminous coal
Passing steam over incandescent coke
Passing air and a large amount of steam over waste coal at about 650°C
Reversed Joule cycle is known as
Carnot cycle
Bell-Coleman cycle
Rankine cycle
Stirling cycle
When a bar is cooled to - 5°C, it will develop
No stress
Shear stress
Tensile stress
Compressive stress
The root mean square velocity of the gas molecules is given by (where k = Boltzmann's constant, T = Absolute temperature, and m = Mass of one molecule of a gas)
√(KT/m)
√(2KT/m)
√(3KT/m)
√(5KT/m)
Kelvin-Planck's law deals with
Conservation of work
Conservation of heat
Conversion of heat into work
Conversion of work into heat
When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This statement is called
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
Kelvin Planck's law
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
The efficiency of Diesel cycle approaches to Otto cycle efficiency when
Cut-off is increased
Cut-off is decreased
Cut-off is zero
Cut-off is constant
The atomic mass of nitrogen is __________ oxygen.
Equal to
Less than
More than
None of these