In an isothermal process,
There is no change in temperature
There is no change in enthalpy
There is no change in internal energy
All of these
Correct Answer :
D. All of these
Related Questions
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
The ratio of elongation in a prismatic bar due to its own weight (W) as compared to another similar bar carrying an additional weight (W) will be
1 : 2
1 : 3
1 : 4
1 : 2.5
The compression ratio for petrol engines is
3 to 6
5 to 8
10 to 20
15 to 30
The columns whose slenderness ratio is less than 80, are known as
Short columns
Long columns
Weak columns
Medium columns
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.
In a steady flow process, the ratio of
Heat transfer is constant
Work transfer is constant
Mass flow at inlet and outlet is same
All of these
Two closely coiled helical springs 'A' and 'B' are equal in all respects but the number of turns of spring 'A' is half that of spring 'B' The ratio of deflections in spring 'A' to spring 'B' is
1/8
1/4
1/2
2
The ratio of root mean square velocity to average velocity of gas molecules at a particular temperature is
0.086
1.086
1.086
4.086
Which of the following materials is most elastic?
Rubber
Plastic
Brass
Steel
The atomic mass of oxygen is
12
14
16
32
A key is subjected to side pressure as well at shearing forces. These pressures are called
Bearing stresses
Fatigue stresses
Crushing stresses
Resultant stresses
A series of operations, which takes place in a certain order and restore the initial conditions at the end, is known as
Reversible cycle
Irreversible cycle
Thermodynamic cycle
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
Coke is produced
When coal is first dried and then crushed to a fine powder by pulverising machine
From the finely ground coal by moulding under pressure with or without a binding material
When coal is strongly heated continuously for 42 to 48 hours in the absence of air in a closed vessel
By heating wood with a limited supply of air to a temperature not less than 280°C
The maximum diameter of the hole that can be punched from a plate of maximum shear stress 1/4th of its maximum crushing stress of punch, is equal to (where t = Thickness of the plate)
t
2t
4t
8t
The ratio of direct stress to volumetric strain in case of a body subjected to three mutually perpendicular stresses of equal intensity, is equal to
Young's modulus
Bulk modulus
Modulus of rigidity
Modulus of elasticity
One kilowatt is equal to
1 N-m/s
100 N-m
1000 N-m/s
1 × 106 N-m/s
An open cycle gas turbine works on
Carnot cycle
Otto cycle
Joule's cycle
Stirling cycle
Which of the following statement is wrong?
The deformation of the bar per unit length in the direction of the force is called linear strain.
The Poisson's ratio is the ratio of lateral strain to the linear strain.
The ratio of change in volume to the original volume is called volumetric strain.
The bulk modulus is the ratio of linear stress to the linear strain.
The heat and work are mutually convertible. This statement is called __________ law of thermodynamics.
Zeroth
First
Second
Third
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)
When a body is subjected to two equal and opposite pushes, as a result of which the body tends to reduce its length, then
The stress and strain induced is compressive
The stress and strain induced is tensile
Both A and B is correct
None of these
When a gas is heated, change takes place in
Pressure
Volume
Temperature
All of these
The gas constant (R) is equal to the
Sum of two specific heats
Difference of two specific heats
Product of two specific heats
Ratio of two specific heats
The moment of resistance of a balanced reinforced concrete beam is based on the stresses in
Steel only
Concrete only
Steel and concrete both
None of these
The pull required to crush the rivet per pitch length is
p.t.σt
d.t.σc
π/4 × d² × σt
π/4 × d² × σc
When shear force at a point is zero, then bending moment is _________ at that point.
Zero
Minimum
Maximum
Infinity
The relation between equivalent length (L) and actual length (l) of a column for both ends fixed is
L = l/2
L = l/√2
L = l
L = 2l
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
A body is subjected to a tensile stress of 1200 MPa on one plane and another tensile stress of 600 MPa on a plane at right angles to the former. It is also subjected to a shear stress of 400 MPa on the same planes. The maximum normal stress will be
400 MPa
500 MPa
900 MPa
1400 MPa