Which of the following is the correct statement?
All the reversible engines have the same efficiency.
All the reversible and irreversible engines have the same efficiency.
Irreversible engines have maximum efficiency.
All engines are designed as reversible in order to obtain maximum efficiency.
Correct Answer :
C. Irreversible engines have maximum efficiency.
Related Questions
For the same compression ratio, the efficiency of Diesel cycle is __________ Otto cycle.
Greater than
Less than
Equal to
None of these
One molecule of oxygen consists of __________ atoms of oxygen.
2
4
8
16
Which of the following gas is mostly used in town for street and domestic lighting and heating?
Producer gas
Coal gas
Mond gas
Coke oven gas
The amount of heat generated per kg of fuel is known as
Calorific value
Heat energy
Lower calorific value
Higher calorific value
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
A composite bar made up of steel and copper bars of equal lengths are heated through 100°C. The stresses developed shall be
Tensile in both the material
Tensile in steel and compressive in copper
Compressive in steel and tensile in copper
Compressive in both the materials
The total energy of a molecule is shared equally by the various degrees of freedom possessed by it. This law is known as
Law of equipartition of energy
Law of conservation of energy
Law of degradation of energy
None of these
The radius of the Mohrs circle in the given figure is equal to
Sum of two principal stresses
Difference of two principal stresses
Half the sum of two principal stresses
Half the difference of two principal stresses
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
The absolute zero temperature is taken as
237°C
-273°C
-237°C
273°C
In closed cycle gas turbine, the air is compressed
Isothermally
Isentropically
Polytropically
None of these
The smallest quantity of a substance, which can exist by itself in a chemically recognizable form is known as
Element
Compound
Atom
Molecule
The efficiency of Carnot cycle is maximum for
Gas engine
Petrol engine
Steam engine
Reversible engine
A definite area or a space where some thermodynamic process takes place is known as
Thermodynamic system
Thermodynamic cycle
Thermodynamic process
Thermodynamic law
The gas in cooling chamber of a closed cycle gas turbine is cooled at
Constant volume
Constant temperature
Constant pressure
None of these
The weakest section of a diamond riveting is the section which passes through
The first row
The second row
The central row
One rivet hole of the end row
Stirling and Ericsson cycles are
Reversible cycles
Irreversible cycles
Semi-reversible cycles
Adiabatic irreversible cycles
The maximum shear stress, in the given figure, is equal to __________ of the Mohr's circle.
Radius
Diameter
Circumference
Area
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
In S. I. units, the value of the universal gas constant is
8.314 J/kg mole-K
83.14 J/kgmole-K
831.4 J/kgmole-K
8314 J/kgmole-K
The shape of cantilever for uniformly distributed load will be
Straight line
Parabolic
Elliptical
Cubic
A column that fails due to direct stress, is called
Short column
Long column
Weak column
Medium column
A steel bar of 5 mm is heated from 25°C to 45°C and it is free to expand. The bar will induce
No stress
Shear stress
Tensile stress
Compressive stress
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
If a part is constrained to move and heated, it will develop
Principal stress
Tensile stress
Compressive stress
Shear stress
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
When gas is heated at constant pressure, the heat supplied is utilised in
Increasing the internal energy of gas
Doing some external work
Increasing the internal energy of gas and also for doing some external work
None of the above
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
In a free expansion process,
W1 - 2 = 0
Q1 - 2 = 0
dU = 0
All 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