The smallest quantity of a substance, which can exist by itself in a chemically recognizable form is known as
Element
Compound
Atom
Molecule
Correct Answer :
D. Molecule
Related Questions
The bending moment of a cantilever beam of length l and carrying a uniformly distributed load of w per unit length is __________ at the fixed end.
wl/4
wl/2
wl
wl²/2
The materials having same elastic properties in all directions are called
Ideal materials
Uniform materials
Isotropic materials
Piratical materials
The heating of a gas at constant pressure is governed by
Boyle's law
Charles' law
Gay-Lussac law
Avogadro's law
The torsional rigidity of a shaft is expressed by the
Maximum torque it can transmit
Number of cycles it undergoes before failure
Elastic limit up to which it resists torsion, shear and bending stresses
Torque required to produce a twist of one radian per unit length of shaft
A pressure vessel is said to be a thick shell, when
It is made of thick sheets
The internal pressure is very high
The ratio of wall thickness of the vessel to its diameter is less than 1/10.
The ratio of wall thickness of the vessel to its diameter is greater than 1/10.
A cycle consisting of two adiabatic and two constant pressure processes is known as
Otto cycle
Ericsson cycle
Joule cycle
Stirling cycle
The shear force diagram for a simply supported beam carrying a uniformly distributed load of w per unit length, consists of
One right angled triangle
Two right angled triangles
One equilateral triangle
Two equilateral triangles
Formula based on IS codes is based on
Straight line formula
Eulers formula
Rankines formula
Secant formula
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
Which of the following has the highest calorific value?
Peat
Lignite
Bituminous coal
Anthracite coal
In an extensive property of a thermodynamic system
Extensive heat is transferred
Extensive work is done
Extensive energy is utilised
None of these
The property of a material which allows it to be drawn into a smaller section is called
Plasticity
Ductility
Elasticity
Malleability
Which of the following statement is correct?
The heat and work are boundary phenomena
The heat and work represent the energy crossing the boundary of the system
The heat and work are path functions
All of the above
The rivets are used for __________ fastenings.
Permanent
Temporary
Semi-permanent
None of these
The bending equation is
M/I = σ/y = E/R
T/J = τ/R = Cθ/l
M/R = T/J = Cθ/l
T/l= τ/J = R/Cθ
The tensile strength of the welded joint for double fillet is (where s = Leg or size of the weld, l = Length of weld, and σt = Allowable tensile stress for weld metal)
0.5 s.l.σt
s.l.σt
√2 s.l.σt
2.s.l.σt
The buckling load for a given material depends on
Slenderness ratio and area of cross-section
Poisson's ratio and modulus of elasticity
Slenderness ratio and modulus of elasticity
Slenderness ratio, area of cross-section and modulus of elasticity
A thin mild steel wire is loaded by adding loads in equal increments till it breaks. The extensions noted with increasing loads will behave as under
Uniform throughout
Increase uniformly
First increase and then decrease
Increase uniformly first and then increase rapidly
In a belt drive, the pulley diameter is doubled, the belt tension and pulley width remaining same. The changes required in key will be
Increase key length
Increase key depth
Increase key width
Double all the dimensions
When the gas is heated at constant pressure, the heat supplied
Increases the internal energy of the gas
Increases the temperature of the gas
Does some external work during expansion
Both (B) and (C)
The value of cp/cv for air is
1
1.4
1.45
2.3
In order to prevent crushing of masonry at the base of the dam, the maximum stress should be __________ the permissible stress of the soil.
Equal to
Less than
More than
None of these
The gas turbine cycle with regenerator improves
Thermal efficiency
Work ratio
Avoids pollution
None of these
The efficiency of Carnot cycle is maximum for
Gas engine
Petrol engine
Steam engine
Reversible engine
The lower layer of the beam as shown in the below figure, will be
In tension
In compression
Neither in tension nor in compression
None of these
In S. I. units, the value of the universal gas constant is
8.314 J/kg mole-K
83.14 J/kgmole-K
831.4 J/kgmole-K
8314 J/kgmole-K
Select the wrong statement
A Joule cycle consists of two constant volume and two isentropic processes.
An Otto cycle consists of two constant volume and two isentropic processes.
An Ericsson cycle consists of two constant pressure and two isothermal processes.
All of the above
Workdone in a free expansion process is
Zero
Minimum
Maximum
Positive
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
The hard coke is obtained when carbonisation of coal is carried out at
300° to 500°C
500° to 700°C
700° to 900°C
900° to 1100°C