When gas is heated at constant pressure, the heat supplied is utilised in
Increasing the internal energy of gas
Doing some external work
Increasing the internal energy of gas and also for doing some external work
None of the above
Correct Answer :
C. Increasing the internal energy of gas and also for doing some external work
Related Questions
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
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 fuel mostly used in cement industry and in metallurgical processes is
Wood charcoal
Bituminous coke
Pulverised coal
Coke
When two bodies are in thermal equilibrium with a third body, they are also in thermal equilibrium with each other. This statement is called
Zeroth law of thermodynamics
First law of thermodynamics
Second law of thermodynamics
Kelvin Planck's law
The total strain energy stored in a body is termed a
Resilience
Proof resilience
Modulus of resilience
Toughness
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
The value of cp/cv for air is
1
1.4
1.45
2.3
A concentrated load is one which
Acts at a point on a beam
Spreads non-uniformly over the whole length of a beam
Spreads uniformly over the whole length of a beam
Varies uniformly over the whole length of a beam
Stirling and Ericsson cycles are
Reversible cycles
Irreversible cycles
Semi-reversible cycles
Adiabatic irreversible cycles
Carnot cycle has maximum efficiency for
Petrol engine
Diesel engine
Reversible engine
Irreversible engine
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 maximum 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]
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
The condition for the reversibility of a cycle is
The pressure and temperature of the working substance must not differ, appreciably, from those of the surroundings at any stage in the process
All the processes, taking place in the cycle of operation, must be extremely slow
The working parts of the engine must be friction free
All of the above
A continuous beam is one which is
Fixed at both ends
Fixed at one end and free at the other end
Supported on more than two supports
Extending beyond the supports
The variables which control the physical properties of a perfect gas are
Pressure exerted by the gas
Volume occupied by the gas
Temperature of the gas
All of these
The deformation of a bar under its own weight is _________ the deformation, if the same body is subjected to a direct load equal to weight of the body.
Equal to
Half
Double
Quadruple
The maximum tangential stress in a thick cylindrical shell is always _________ the internal pressure acting on the shell.
Equal to
Less than
Greater than
None of these
The gas in cooling chamber of a closed cycle gas turbine is cooled at
Constant volume
Constant temperature
Constant pressure
None of these
The change of entropy, when heat is absorbed by the gas, is
Positive
Negative
Positive or negative
None of these
In open cycle gas turbine plants
The indirect heat exchanger and cooler is avoided
Direct combustion system is used
A condenser is used
All of the above
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
One kg of carbon monoxide requires __________ kg of oxygen to produce 11/7 kg of carbon dioxide gas.
4/7
11/4
9/7
All of these
For which material the Poisson's ratio is more than unity
Steel
Copper
Aluminium
None of the above
The efficiency of Diesel cycle with decrease in cut-off
Increases
Decreases
First increases and then decreases
First decreases and then increases
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
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
If the value of n = 0 in the equation pvn = C, then the process is called
Constant volume process
Adiabatic process
Constant pressure process
Isothermal process
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 absolute zero pressure will be
When molecular momentum of the system becomes zero
At sea level
At the temperature of - 273 K
At the centre of the earth
Slenderness of a column is zero when
Ends are firmly fixed
Column is supported on all sides throughout the length
Length is equal to radius of gyration
Length is twice the radius of gyration