In the tensile test, the phenomenon of slow extension of the material, i. e. stress increasing with the time at a constant load is called
Creeping
Yielding
Breaking
Plasticity
Correct Answer :
A. Creeping
Related Questions
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 compression ratio for petrol engines is
3 to 6
5 to 8
15 to 20
20 to 30
Kelvin-Planck's law deals with
Conservation of work
Conservation of heat
Conversion of heat into work
Conversion of work into heat
The efficiency of Diesel cycle increases with
Decrease in cut-off
Increase in cut-off
Constant cut-off
None of these
An open system is one in which
Heat and work crosses the boundary of the system, but the mass of the working substance does not crosses the boundary of the system
Mass of the working substance crosses the boundary of the system but the heat and work does not crosses the boundary of the system
Both the heat and work as well as mass of the working substance crosses the boundary of the system
Neither the heat and work nor the mass of the working substance crosses the boundary of the system
For a simply supported beam of length l, when a concentrated load W is applied in the centre of the beam, the maximum deflection is
5WL³/ 384EI
WL³/384EI
WL³/ 348EI
WL³/ 48EI
The deformation of a bar under its own weight is _________ the deformation, if the same body is subjected to a direct load equal to weight of the body.
Equal to
Half
Double
Quadruple
Stirling and Ericsson cycles are
Reversible cycles
Irreversible cycles
Semi-reversible cycles
Adiabatic irreversible cycles
The value of cp/cv for air is
1
1.4
1.45
2.3
The deformation per unit length is called
Tensile stress
Compressive stress
Shear stress
Strain
The maximum tangential stress in a thick cylindrical shell is always _________ the internal pressure acting on the shell.
Equal to
Less than
Greater than
None of these
Which of the following is the extensive property of a thermodynamic system?
Pressure
Volume
Temperature
Density
The strain energy stored in a body due to suddenly applied load compared to when it is applied gradually is
Same
Twice
Four times
Eight times
Which of the following gas has a minimum molecular mass?
Oxygen
Nitrogen
Hydrogen
Methane
The __________ is obtained when carbonisation of coal is carried out at 500° to 700° C.
Soft coal
Hard coal
Pulverised coal
Bituminous coal
The main cause for the irreversibility is
Mechanical and fluid friction
Unrestricted expansion
Heat transfer with a finite temperature difference
All of the above
Select the correct statement as per Charles' law
p.v = constant, if T is kept constant
v/T = constant, if p is kept constant
p/T = constant, if v is kept constant
T/p = constant, if v is kept constant
When a body is subjected to a direct tensile stress (σx) in one plane accompanied by a simple shear stress (τxy), the minimum normal 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)
Which is the false statement about true stress strain method?
It does not exist
It is more sensitive to changes in both metallurgical and mechanical conditions
It gives a more accurate picture of the ductility
It can be correlated with stress strain values in other tests like torsion, impact, combined stress tests etc.
In a prismatic member made of two materials so joined that they deform equally under axial stress, the unit stresses in two materials are
Equal
Proportional to their respective moduli of elasticity
Inversely proportional to their moduli of elasticity
Average of the sum of moduli of elasticity
The ratio of lateral strain to the linear strain within elastic limit is known as
Young's modulus
Bulk modulus
Modulus of rigidity
Poisson's ratio
Mond gas is obtained by
Partial combustion of coal, coke, anthracite coal or charcoal in a mixed air steam blast
Carbonisation of bituminous coal
Passing steam over incandescent coke
Passing air and a large amount of steam over waste coal at about 650°C
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
One kg of carbon monoxide requires __________ kg of oxygen to produce 11/7 kg of carbon dioxide gas.
4/7
11/4
9/7
All of these
A fletched beam is used to
Change the shape of the beam
Effect the saving in material
Equalise the strength in tension and compression
Increase the cross-section of the beam
The efficiency of the Carnot cycle is (where T1 and T2 = Highest and lowest temperature during the cycle)
(T1/T2) - 1
1 - (T1/T2)
1 - (T2/T1)
1 + (T2/T1)
The natural petroleum may be separated into
Petrol
Kerosene
Fuel oil
Lubricating oil
Which of the following cycles has maximum efficiency?
Rankine
Stirling
Carnot
Brayton
The efficiency of the Carnot cycle may be increased by
Increasing the highest temperature
Decreasing the highest temperature
Increasing the lowest temperature
Keeping the lowest temperature constant
The state of stress at a point in a loaded member is shown in the below figure. The magnitude of maximum shear stress is
10 MPa
30 MPa
50 MPa
100 MPa