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
Correct Answer :
D. All of these
Related Questions
When a body is subjected to a direct tensile stress (σx) in one plane accompanied by a simple shear stress (τxy), the maximum shear stress is
(σx/2) + (1/2) × √(σx² + 4 τ²xy)
(σx/2) - (1/2) × √(σx² + 4 τ²xy)
(σx/2) + (1/2) × √(σx² - 4 τ²xy)
(1/2) × √(σx² + 4 τ²xy)
Flow stress corresponds to
Fluids in motion
Breaking point
Plastic deformation of solids
Rupture stress
In the below figure, curve D represents_________.
Mild steel
Cast iron
Concrete
Bone of these
The neutral axis of the cross-section a beam is that axis at which the bending stress is
Zero
Minimum
Maximum
Infinity
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
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
The shaft 'A' has the greater diameter
Both are of same diameter
None of these
The increase in entropy of a system represents
Increase in availability of energy
Increase in temperature
Decrease in pressure
Degradation of energy
Second law of thermodynamics defines
Heat
Work
Internal energy
Entropy
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
The ultimate analysis of coal consists of the determination of the percentage of
Carbon
Hydrogen and nitrogen
Sulphur and ash
All of these
The heat and work are mutually convertible. This statement is called __________ law of thermodynamics.
Zeroth
First
Second
Third
The bending moment of a cantilever beam of length l and carrying a uniformly distributed load of w per unit length is __________ at the fixed end.
wl/4
wl/2
wl
wl²/2
An isothermal process is governed by
Boyle's law
Charles' law
Gay-Lussac law
Avogadro's law
The most probable velocity of the gas molecules is given by
√(KT/m)
√(2KT/m)
√(3KT/m)
√(5KT/m)
A beam which is fixed at one end and free at the other is called
Simply supported beam
Fixed beam
Overhanging beam
Cantilever beam
The atomic mass of sulphur is
12
14
16
32
The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is always __________ one.
Equal to
Less than
Greater than
None of these
The variables which control the physical properties of a perfect gas are
Pressure exerted by the gas
Volume occupied by the gas
Temperature of the gas
All of these
In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be
Increase key length
Increase key depth
Increase key width
Double all the dimensions
Shear stress induced in a shaft subjected to tension will be
Maximum at periphery and zero at center
Maximum at center
Uniform throughout
None of the above
Which of the following gas has the highest calorific value?
Coal gas
Producer gas
Mond gas
Blast furnace gas
A cantilever beam is one which is
Fixed at both ends
Fixed at one end and free at the other end
Supported at its ends
Supported on more than two supports
The efficiency of Stirling cycle is __________ Carnot cycle.
Greater than
Less than
Equal to
None of these
A continuous beam is one which is
Fixed at both ends
Fixed at one end and free at the other end
Supported on more than two supports
Extending beyond the supports
For a beam, as shown in the below figure, when the load W is applied in the centre of the beam, the maximum deflection is
Wl3 / 48EI
5Wl3 / 384EI
Wl3 / 392EI
Wl3 / 384EI
The condition for the reversibility of a cycle is
The pressure and temperature of the working substance must not differ, appreciably, from those of the surroundings at any stage in the process
All the processes, taking place in the cycle of operation, must be extremely slow
The working parts of the engine must be friction free
All of the above
The efficiency of Carnot cycle depends upon
Temperature limits
Pressure ratio
Volume compression ratio
Cut-off ratio and compression ratio
Stirling cycle consists of
Two constant volume and two isentropic processes
Two constant volume and two isothermal processes
Two constant pressure and two isothermal processes
One constant volume, one constant pressure and two isentropic processes
High air-fuel ratio in gas turbines
Increases power output
Improves thermal efficiency
Reduces exhaust temperature
Do not damage turbine blades
For which material the Poisson's ratio is more than unity
Steel
Copper
Aluminium
None of the above