Workdone in a free expansion process is
Zero
Minimum
Maximum
Positive
Correct Answer :
A. Zero
Related Questions
A cycle consisting of two adiabatic and two constant pressure processes is known as
Otto cycle
Ericsson cycle
Joule cycle
Stirling cycle
Stirling and Ericsson cycles are
Reversible cycles
Irreversible cycles
Semi-reversible cycles
Adiabatic irreversible cycles
The absolute zero temperature is taken as
237°C
-273°C
-237°C
273°C
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
The relation between Young's modulus (E), shear modulus (C) and bulk modulus (K) is given by
E = 3K.C/(3K + C)
E = 6K.C/(3K + C)
E = 9K.C/(3K + C)
E = 12K.C/(3K + C)
The natural solid fuel is
Wood
Coke
Anthracite coal
Pulverised coal
The buckling load for a given column depends upon
Area of cross-section of the column
Length and least radius of gyration of the column
Modulus of elasticity for the material of the column
All of the above
The process is adiabatic, if the value of n in the equation pvn = C, is
0
1
γ
∝
The neutral axis of the cross-section a beam is that axis at which the bending stress is
Zero
Minimum
Maximum
Infinity
The reading of the pressure gauge fitted on a vessel is 25 bar. The atmospheric pressure is 1.03 bar and the value of 'g' is 9.81 m/s2. The absolute pressure in the vessel is
23.97 bar
25 bar
26.03 bar
34.81 bar
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
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
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 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 point of contraflexure is a point where
Shear force changes sign
Bending moment changes sign
Shear force is maximum
Bending moment is maximum
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 heat flows from a cold body to a hot body with the aid of an external source. This statement is given by
Kelvin
Joule
Clausis
Gay-Lussac
The deformation of a bar under its own weight compared to the deformation of same body subjected to a direct load equal to weight of the body is
Same
Double
Half
Four times
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
Tensile strength of a material is obtained by dividing the maximum load during the test by the
Area at the time of fracture
Original cross-sectional area
Average of (A) and (B)
Minimum area after fracture
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
For riveting, the size of hole drilled in plates is __________ shank diameter of rivet.
Equal to
Less than
Greater than
None of these
The following cycle is used for air craft refrigeration
Brayton cycle
Joule cycle
Carnot cycle
Reversed Brayton cycle
The layer at the centre of gravity of the beam as shown in the below figure, will be
In tension
In compression
Neither in tension nor in compression
None of these
The property of a material which allows it to be drawn into a smaller section is called
Plasticity
Ductility
Elasticity
Malleability
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
In the torsion equation T/J = τ/r = Gθ/ L, the term J/R is called
Shear modulus
Section modulus
Polar modulus
None of these
The __________ states that change of internal energy of a perfect gas is directly proportional to the change of temperature.
Boyle's law
Charle's law
Gay-Lussac law
Joule's law
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
A body is subjected to a direct tensile stress of 300 MPa in one plane accompanied by a simple shear stress of 200 MPa. The maximum shear stress will be
-100 MPa
250 MPa
300 MPa
400 MPa