True stress strain-curve for materials is plotted between
Load/original cross-sectional area and change in length/original length
Load/ instantaneous cross-sectional area and loge (original area/ instantaneous area)
Load/ instantaneous cross-sectional area and change in length/ original length
Load/ instantaneous area and instantaneous area/original area
Correct Answer :
B. Load/ instantaneous cross-sectional area and loge (original area/ instantaneous area)
Related Questions
A key is subjected to side pressure as well at shearing forces. These pressures are called
Bearing stresses
Fatigue stresses
Crushing stresses
Resultant stresses
The extremeties of any diameter on Mohr's circle represent
Principal stresses
Normal stresses on planes at 45°
Shear stresses on planes at 45°
Normal and shear stresses on a plane
If in the equation pvn = C, the value of n = ∝, then the process is called
Constant volume process
Adiabatic process
Constant pressure process
Isothermal process
The efficiency of the dual combustion cycle for the same compression ratio is __________ Diesel cycle.
Greater than
Less than
Equal to
None of these
The sum of internal energy (U) and the product of pressure and volume (p.v) is known as
Workdone
Entropy
Enthalpy
None of these
The bending stress in a beam is _________ section modulus.
Inversely proportional to two times
Directly proportional to
Inversely proportional to
None of these
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 polytropic index (n) is given by
log (p1p2)/log (v1v2)
log (p2/ p1)/log (v1/ v2)
log (v1/ v2)/ log (p1/p2)
log [(p1v1)/(p2v2)]
Modulus of rigidity is defined as the ratio of
Longitudinal stress to longitudinal strain
Volumetric stress to volumetric strain
Lateral stress to Lateral strain
Shear stress to shear strain
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
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
Which is the incorrect statement about Carnot cycle?
It is used as the alternate standard of comparison of all heat engines.
All the heat engines are based on Carnot cycle.
It provides concept of maximising work output between the two temperature limits.
All of the above
Second law of thermodynamics defines
Heat
Work
Internal energy
Entropy
Stirling cycle consists of
Two constant volume and two isentropic processes
Two constant volume and two isothermal processes
Two constant pressure and two isothermal processes
One constant volume, one constant pressure and two isentropic processes
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
One kg of carbon produces __________ kg of carbon dioxide.
3/7
7/3
11/3
3/11
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
Carnot cycle has maximum efficiency for
Petrol engine
Diesel engine
Reversible engine
Irreversible engine
The efficiency and work ratio of a simple gas turbine cycle are
Low
Very low
High
Very high
A close cycle gas turbine gives __________ efficiency as compared to an open cycle gas turbine.
Same
Lower
Higher
None of these
A process, in which the working substance neither receives nor gives out heat to its surroundings during its expansion or compression, is called
Isothermal process
Hyperbolic process
Adiabatic process
Polytropic process
The heat energy stored in the gas and used for raising the temperature of the gas is known as
External energy
Internal energy
Kinetic energy
Molecular energy
The total elongation produced in a bar of uniform section hanging vertically downwards due to its own weight is equal to that produced by a weight
Of same magnitude as that of bar and applied at the lower end
Half the weight of bar applied at lower end
Half of the square of weight of bar applied at lower end
One fourth of weight of bar applied at lower end
According to Kelvin-Planck's statement of second law of thermodynamics,
It is impossible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
It is possible to construct an engine working on a cyclic process, whose sole purpose is to convert heat energy into work
It is impossible to construct a device which operates in a cyclic process and produces no effect other than the transfer of heat from a cold body to a hot body
None of the above
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 point of contraflexure is a point where
Shear force changes sign
Bending moment changes sign
Shear force is maximum
Bending moment is maximum
Resilience of a material is considered when it is subjected to
Frequent heat treatment
Fatigue
Creep
Shock loading
In closed cycle gas turbine, the air is compressed
Isothermally
Isentropically
Polytropically
None of these
Which of the following cycles has maximum efficiency?
Rankine
Stirling
Carnot
Brayton
Which of the following cycles is not a reversible cycle?
Carnot
Ericsson
Stirling
None of the above