A material obeys hooks law up to
Plastic limit
Elastic limit
Yield point
Limit of proportionality
Correct Answer :
B. Elastic limit
Related Questions
When wood is heated with a limited supply of air to a temperature not less than 280°C, the resulting fuel is
Coke
Wood charcoal
Bituminous coal
Briquetted coal
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
The universal gas constant (or molar constant) of a gas is the product of
Molecular mass of the gas and the gas constant
Atomic mass of the gas and the gas constant
Molecular mass of the gas and the specific heat at constant pressure
Molecular mass of the gas and the specific heat at constant volume
Which of the following is correct?
Absolute pressure = Gauge pressure + Atmospheric pressure
Gauge pressure = Absolute pressure + Atmospheric pressure
Atmospheric pressure = Absolute pressure + Gauge pressure
Absolute pressure = Gauge pressure - Atmospheric pressure
The value of Poisson's ratio for steel is between
0.01 to 0.1
0.23 to 0.27
0.25 to 0.33
0.4 to 0.6
When a body is subjected to a direct tensile stress (σ) in one plane, then maximum normal stress occurs at a section inclined at __________ to the normal of the section.
0°
30°
45°
90°
After reaching the yielding stage while testing a mild steel specimen, strain
Becomes constant
Starts decreasing
Increases without any increase in load
None of the above
The maximum shear stress, in the given figure, is equal to __________ of the Mohr's circle.
Radius
Diameter
Circumference
Area
Resilience of a material is considered when it is subjected to
Frequent heat treatment
Fatigue
Creep
Shock loading
The processes occuring in open system which permit the transfer of mass to and from the system, are known as
Flow processes
Non-flow processes
Adiabatic processes
None of these
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
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
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
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
The shear force at the centre of a simply supported beam with a gradually varying load from zero at both ends to w per metre at the centre, is
Zero
wl/4
wl/2
wl²/2
The ratio of maximum shear stress developed in a rectangular beam and a circular beam of the same cross-sectional area is
2/3
3/4
1
9/8
When a closely-coiled helical spring of mean diameter (D) is subjected to an axial load (W), the deflection of the spring (δ) is given by (where d = Diameter of spring wire, n = No. of turns of the spring, and C = Modulus of rigidity for the spring material)
WD3n/Cd⁴
2WD3n/Cd⁴
4WD3n/Cd⁴
8WD3n/Cd⁴
Stirling and Ericsson cycles are
Reversible cycles
Irreversible cycles
Semi-reversible cycles
Quasi-static cycles
Which of the following statement is incorrect?
The liquid fuels have higher calorific value than solid fuels
The solid fuels have higher calorific value than liquid fuels
A good fuel should have low ignition point
The liquid fuels consist of hydrocarbons
The property of a working substance which increases or decreases as the heat is supplied or removed in a reversible manner, is known as
Enthalpy
Internal energy
Entropy
External energy
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
Shear modulus is the ratio of
Linear stress to linear strain
Linear stress to lateral strain
Volumetric strain to linear strain
Shear stress to shear strain
Volumetric strain for a rectangular specimen of length l, breadth b and thickness t subjected to a pull of P is given by
e (1 - 2m)
e (1 - 2/m)
e (m - 2)
e (2/m - 1)
A riveted joint in which the number otrivets decrease from innermost to outer most rows is called
Chain riveted joint
Diamond riveted joint
Crisscross riveted joint
Zigzag riveted joint
When the gas is heated at constant volume, the heat supplied
Increases the internal energy of the gas and increases the temperature of the gas
Does some external work during expansion
Both (A) and (B)
None of these
When a closely-coiled helical spring of mean diameter (D) is subjected to an axial load (W), the stiffness of the spring is given by
Cd⁴/D3n
Cd⁴/2D3n
Cd⁴/4D3n
Cd⁴/8D3n
The value of gas constant (R) in S. I. units is
0.287 J/kgK
2.87 J/kgK
28.7 J/kgK
287 J/kgK
Diesel cycle consists of __________ processes.
Two constant volume and two isentropic
Two constant pressure and two isentropic
Two constant volume and two isothermal
One constant pressure, one constant volume and two isentropic
Youngs modulus of a wire is defined as the stress which will increase the length of wire compared to its original length by
Half
Same amount
Double
One-fourth
The efficiency of Stirling cycle is __________ Carnot cycle.
Greater than
Less than
Equal to
None of these