The entropy __________ in an irreversible cyclic process.
Remains constant
Decreases
Increases
None of these
Correct Answer :
C. Increases
Related Questions
The work ratio of a gas turbine plant 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)
A material obeys hooks law up to
Plastic limit
Elastic limit
Yield point
Limit of proportionality
The limit of eccentricity for no tensile conditions for a column of circular section of diameter (D) is
d/4
d/8
d/12
d/16
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
The value of modulus of elasticity for mild steel is of the order of
2.1 × 10⁵ kg/cm²
2.1 × 10⁶ kg/cm²
2.1 × 10⁷ kg/cm²
0.1 × 10⁶ kg/cm²
Elasticity of Mild Steel specimen is defined by
Hookes law
Yield point
Plastic flow
Proof stress
The compression ratio for petrol engines is
3 to 6
5 to 8
10 to 20
15 to 30
A vertical column has two moments of inertia (i.e. Ixx and Iyy ). The column will tend to buckle in the direction of the
Axis of load
Perpendicular to the axis of load
Maximum moment of inertia
Minimum moment of inertia
The value of 1 mm of Hg is equal to
1.333 N/m2
13.33 N/m2
133.3 N/m2
1333 N/m2
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
A circular shaft fixed at, A has diameter D for half of its length and diameter D/2 over the other half, as shown in the below figure. If the rotation of B relative to A is 0.1 radian, the rotation of C relative to B will be
0.4 radian
0.8 radian
1.6 radian
3.2 radian
The extension of a circular bar tapering uniformly from diameter d₁ at one end to diameter d₂ at the other end and subjected to an axial pull of P is given by
δl = 4PE/ πl²
δl = 4πld²/PE
δl = 4Pl/πEd₁d₂
δl = 4PlE/ πd₁d₂
The work ratio of simple gas turbine cycle depends upon
Maximum cycle temperature
Minimum cycle temperature
Pressure ratio
All of these
One molecule of oxygen is __________ times heavier than the hydrogen atom.
12
14
16
32
Which of the following is the correct statement?
For a given compression ratio, both Otto and Diesel cycles have the same efficiency.
For a given compression ratio, Otto cycle is more efficient than Diesel cycle.
For a given compression ratio, Diesel cycle is more efficient than Otto cycle.
The efficiency of Otto or Diesel cycle has nothing to do with compression ratio.
The heat absorbed or rejected by the working substance is given by (where ds = Increase or decrease of entropy, T = Absolute temperature, and dQ = Heat absorbed or rejected)
δQ = T.ds
δQ = T/ds
dQ = ds/T
None of these
The compression ratio is the ratio of
Swept volume to total volume
Total volume to swept volume
Swept volume to clearance volume
Total volume to clearance volume
The increase in entropy of a system represents
Increase in availability of energy
Increase in temperature
Decrease in pressure
Degradation of energy
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 fuel mostly used in cement industry and in metallurgical processes is
Wood charcoal
Bituminous coke
Pulverised coal
Coke
In a tensile test, near the elastic limit zone, the
Tensile strain increases more quickly
Tensile strain decreases more quickly
Tensile strain increases in proportion to the stress
Tensile strain decreases in proportion to the stress
The pressure exerted by an ideal gas is ________ of the kinetic energy of all the molecules contained in a unit volume of gas.
One-half
One-third
Two-third
Three-fourth
A process, in which the temperature of the working substance remains constant during its expansion or compression, is called
Isothermal process
Hyperbolic process
Adiabatic process
Polytropic process
Which of the following materials is most elastic?
Rubber
Plastic
Brass
Steel
The absolute zero temperature is taken as
-273°C
73°C
237°C
-237°C
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.
The value of shear stress which is induced in the shaft due to the applied couple varies
From maximum at the centre to zero at the circumference
From zero at the centre to maximum at the circumference
From maximum at the centre to minimum at the circumference
From minimum at the centre to maximum at the circumference
The deformation per unit length is called
Tensile stress
Compressive stress
Shear stress
Strain
The temperature at which the volume of a gas becomes zero is called
Absolute scale of temperature
Absolute zero temperature
Absolute temperature
None of these
Which of the following has the minimum atomic mass?
Oxygen
Sulphur
Nitrogen
Carbon