When the expansion or compression takes place according to the law pvn = C, the process is known as
Isothermal process
Adiabatic process
Hyperbolic process
Polytropic process
Correct Answer :
D. Polytropic process
Related Questions
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)
A masonry dam may fail due to
Tension in the masonry of the dam and its base
Overturning of the dam
Crushing of masonry at the base of the dam
Any one of the above
The gas turbine cycle with regenerator improves
Thermal efficiency
Work ratio
Avoids pollution
None of these
The efficiency and work ratio of a simple gas turbine cycle are
Very low
Low
High
Very high
The compression ratio for petrol engines is
3 to 6
5 to 8
10 to 20
15 to 30
When the gas is cooled at constant pressure,
Its temperature increases but volume decreases
Its volume increases but temperature decreases
Both temperature and volume increases
Both temperature and volume decreases
For which material the Poisson's ratio is more than unity
Steel
Copper
Aluminium
None of the above
When a thin cylindrical shell is subjected to an internal pressure, the volumetric strain is (where ε₁ = Hoop strain, and ε₂ = Longitudinal strain)
2ε₁ - ε₂
2ε₁ + ε₂
2ε₂ - ε₁
2ε₂ + ε₁
The unit of energy is S. I. units is
Joule (J)
Joule metre (Jm)
Watt (W)
Joule/metre (J/m)
The value of shear stress which is induced in the shaft due to the applied couple varies
From maximum at the centre to zero at the circumference
From zero at the centre to maximum at the circumference
From maximum at the centre to minimum at the circumference
From minimum at the centre to maximum at the circumference
In compression test, the fracture in cast iron specimen would occur along
The axis of load
An oblique plane
At right angles to the axis of specimen
Would not occur
The principal constituents of a fuel are
Carbon and hydrogen
Oxygen and hydrogen
Sulphur and oxygen
Sulphur and hydrogen
The mass of flue gas per kg of fuel is the ratio of the
Mass of oxygen in 1 kg of flue gas to the mass of oxygen in 1 kg of fuel
Mass of oxygen in 1 kg of fuel to the mass of oxygen in 1 kg of flue gas
Mass of carbon in 1 kg of flue gas to the mass of carbon in 1 kg of fuel
Mass of carbon in 1 kg of fuel to the mass of carbon in 1 kg of flue gas
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
∝
The energy stored in a body when strained within elastic limit is known as
Resilience
Proof resilience
Strain energy
Impact energy
The efficiency and work ratio of a simple gas turbine cycle are
Low
Very low
High
Very high
In a free expansion process,
W1 - 2 = 0
Q1 - 2 = 0
dU = 0
All of these
When a body is subjected to biaxial stress i.e. direct stresses (σx) and (σy) in two mutually perpendicular planes accompanied by a simple shear stress (τxy), then minimum normal stress is
(σx + σy)/2 + (1/2) × √[(σx - σy)² + 4 τ²xy]
(σx + σy)/2 - (1/2) × √[(σx - σy)² + 4 τ²xy]
(σx - σy)/2 + (1/2) × √[(σx + σy)² + 4 τ²xy]
(σx - σy)/2 - (1/2) × √[(σx + σy)² + 4 τ²xy]
Second law of thermodynamics defines
Heat
Work
Internal energy
Entropy
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
According to Kelvin-Planck's statement, a perpetual motion of the __________ is impossible.
First kind
Second kind
Third kind
None of these
One molecule of oxygen consists of __________ atoms of oxygen.
2
4
8
16
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 stress developed in a material at breaking point in extension is called
Breaking stress
Fracture stress
Yield point stress
Ultimate tensile stress
The capacity of a strained body for doing work on the removal of the straining force, is called
Strain energy
Resilience
Proof resilience
Impact energy
One kg of ethylene (C2H4) requires 2 kg of oxygen and produces 22/7 kg of carbon dioxide and __________ kg of water or steam.
9/7
11/7
7/4
1/4
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 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)
A close cycle gas turbine gives __________ efficiency as compared to an open cycle gas turbine.
Same
Lower
Higher
None of these
The deformation of a bar under its own weight compared to the deformation of same body subjected to a direct load equal to weight of the body is
Same
Double
Half
Four times