An adiabatic process is one in which
No heat enters or leaves the gas
The temperature of the gas changes
The change in internal energy is equal to the mechanical workdone
All of the above
Correct Answer :
D. All of the above
Related Questions
A process, in which the temperature of the working substance remains constant during its expansion or compression, is called
Isothermal process
Hyperbolic process
Adiabatic process
Polytropic process
The layer at the centre of gravity of the beam as shown in the below figure, will be
In tension
In compression
Neither in tension nor in compression
None of these
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
A bar of copper and steel form a composite system, which is heated to a temperature of 40°C. The stress induced in the copper bar will be
Tensile
Compressive
Shear
Zero
The moment of resistance of a balanced reinforced concrete beam is based on the stresses in
Steel only
Concrete only
Steel and concrete both
None of these
If a material expands freely due to heating it will develop
Thermal stresses
Tensile stress
Bending
No stress
Second law of thermodynamics defines
Heat
Work
Internal energy
Entropy
One kg of hydrogen requires 8 kg of oxygen and produces
1 kg of water
7 kg of water
8 kg of water
9 kg of water
The shape of cantilever for uniformly distributed load will be
Straight line
Parabolic
Elliptical
Cubic
If the slenderness ratio for a column is 100, then it is said to be a _________ column.
Long
Medium
Short
None of these
The natural solid fuel is
Wood
Coke
Anthracite coal
Pulverised coal
The pull required to tear off the plate per pitch length is (where p = Pitch of rivets, t = Thickness of plates, and σt, τ and σc = Permissible tensile, shearing and crushing stresses respectively)
(p - 2d) t × σc
(p - d) t × τ
(p - d) t × σt
(2p - d) t × σt
The reading of the pressure gauge fitted on a vessel is 25 bar. The atmospheric pressure is 1.03 bar and the value of 'g' is 9.81 m/s2. The absolute pressure in the vessel is
23.97 bar
25 bar
26.03 bar
34.81 bar
For the same maximum pressure and temperature,
Otto cycle is more efficient than Diesel cycle
Diesel cycle is more efficient than Otto cycle
Dual cycle is more efficient than Otto and Diesel cycles
Dual cycle is less efficient than Otto and Diesel cycles
Which of the following has the minimum atomic mass?
Oxygen
Sulphur
Nitrogen
Carbon
The ratio of the largest load in a test to the original cross-sectional area of the test piece is called
Elastic limit
Yield stress
Ultimate stress
Breaking stress
One reversible heat engine operates between 1600 K and T2 K and another reversible heat engine operates between T2 K and 400 K. If both the engines have the same heat input and output, then temperature T2 is equal to
800 K
1000 K
1200 K
1400 K
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
Petrol is distilled at
65° to 220°C
220° to 345°C
345° to 470°C
470° to 550°C
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 general gas energy equation is (where Q1 - 2 = Heat supplied, dU = Change in internal energy, and W1 - 2 = Work done in heat units)
Q1 - 2 = dU + W1 - 2
Q1 - 2 = dU - W1 - 2
Q1 - 2 = dU/W1 - 2
Q1 - 2 = dU × W1 - 2
The assumption made in Euler's column theory is that
The failure of column occurs due to buckling alone
The length of column is very large as compared to its cross-sectional dimensions
The column material obeys Hooke's law
All of the above
The property of a material by virtue of which a body returns to its original, shape after removal of the load is called
Plasticity
Elasticity
Ductility
Malleability
The compression ratio for petrol engines is
3 to 6
5 to 8
10 to 20
15 to 30
Kerosene is distilled at
65° to 220°C
220° to 345°C
345° to 470°C
470° to 550°C
The entropy may be expressed as a function of
Pressure and temperature
Temperature and volume
Heat and work
All of these
Which of the following is the correct statement?
All the reversible engines have the same efficiency.
All the reversible and irreversible engines have the same efficiency.
Irreversible engines have maximum efficiency.
All engines are designed as reversible in order to obtain maximum efficiency.
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
The ratio of specific heat at constant pressure (cp) and specific heat at constant volume (cv) is always __________ one.
Equal to
Less than
Greater than
None of these
The hyperbolic process is governed by
Boyle's law
Charles' law
Gay-Lussac law
Avogadro's law