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
Correct Answer :
B. First law of thermodynamics
Related Questions
A shaft revolving at ω rad/s transmits torque (T) in Nm. The power developed is
T.ω watts
2π. T.ω watts
2π. T.ω/75 watts
2π. T.ω/4500 watts
When a system changes its state from one equilibrium state to another equilibrium state, then the path of successive states through which the system has passed, is known as
Thermodynamic law
Thermodynamic process
Thermodynamic cycle
None of these
The columns whose slenderness ratio is less than 80, are known as
Short columns
Long columns
Weak columns
Medium columns
The torque transmitted by a solid shaft of diameter (D) is (where τ = Maximum allowable shear stress)
π /4 × τ × D³
π /16 × τ × D³
π /32 × τ × D³
π /64 × τ × D³
The materials which exhibit the same elastic properties in all directions are called
Homogeneous
Inelastic
Isotropic
Isentropic
The principal constituents of a fuel are
Carbon and hydrogen
Oxygen and hydrogen
Sulphur and oxygen
Sulphur and hydrogen
Carnot cycle consists of
Two constant volume and two isentropic processes
Two isothermal and two isentropic processes
Two constant pressure and two isentropic processes
One constant volume, one constant pressure and two isentropic processes
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
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°
When coal is strongly heated continuously for 42 to 48 hours in the absence of air in a closed vessel, the process is known as __________ of fuel.
Atomisation
Carbonisation
Combustion
None of these
When a bar is cooled to - 5°C, it will develop
No stress
Shear stress
Tensile stress
Compressive stress
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
For a beam, as shown in the below figure, when the load W is applied in the centre of the beam, the maximum deflection is
Wl3 / 48EI
5Wl3 / 384EI
Wl3 / 392EI
Wl3 / 384EI
Strain is defined as the ratio of
Change in volume to original volume
Change in length to original length
Change in cross-sectional area to original cross-sectional area
Any one 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
The distillation carried out in such a way that the liquid with the lowest boiling point is first evaporated and recondensed, then the liquid with the next higher boiling point is then evaporated and recondensed, and so on until all the available liquid fuels are separately recovered in the sequence of their boiling points. Such a process is called
Cracking
Carbonisation
Fractional distillation
Full distillation
The general law of expansion or compression is pvn = C, The process is said to be hyperbolic, if n is equal to
0
1
γ
∝
A column that fails due to direct stress, is called
Short column
Long column
Weak column
Medium column
Which of the following is the extensive property of a thermodynamic system?
Pressure
Volume
Temperature
Density
Within elastic limit, stress is
Inversely proportional to strain
Directly proportional to strain
Square root of strain
Equal to strain
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
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
The thickness of a thin cylindrical shell with hemispherical ends is __________ that of spherical ends.
Equal to
More than
Less than
None of these
Which of the following is a proper sequence?
Proportional limit, elastic limit, yielding, failure
Elastic limit, proportional limit, yielding, failure
Yielding, proportional limit, elastic limit, failure
None of the above
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
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
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
In the below figure, the stress corresponding to point D is
Yield point stress
Breaking stress
Ultimate stress
Elastic limit
In a uniform bar, supported at one end in position, the maximum stress under self weight of bar shall occur at the
Middle of bar
Supported end
Bottom end
None of these
When a body is subjected to a direct tensile stress (σx) in one plane accompanied by a simple shear stress (τxy), the maximum normal stress i
(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)