The efficiency of a Carnot engine depends on
Working substance
Design of engine
Size of engine
Temperatures of source and sink
Correct Answer :
D. Temperatures of source and sink
Related Questions
In a reversible adiabatic process, the ratio of T1/T2 is equal to
(p2/p1)γ - 1/ γ
(p1/p2)γ - 1/ γ
(v2/v1)γ - 1/ γ
(v1/v2)γ - 1/ γ
The shear force at the centre of a simply supported beam with a gradually varying load from zero at both ends to w per metre at the centre, is
Zero
wl/4
wl/2
wl²/2
The efficiency of Diesel cycle with decrease in cut-off
Increases
Decreases
First increases and then decreases
First decreases and then increases
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
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 principal constituents of a fuel are
Carbon and hydrogen
Oxygen and hydrogen
Sulphur and oxygen
Sulphur and hydrogen
A boiler shell 200 cm diameter and plate thickness 1.5 cm is subjected to internal pressure of 1.5 MN/m, and then the hoop stress will be
30 MN/m²
50 MN/m²
100 MN/m²
200 MN/m²
The value of Poisson's ratio for steel is between
0.01 to 0.1
0.23 to 0.27
0.25 to 0.33
0.4 to 0.6
Steam coal is a
Pulverised coal
Brown coal
Coking bituminous coal
Non-coking bituminous coal
The percentage reduction in area of a cast iron specimen during tensile test would be of the order of
More than 50 %
25-50 %
10-25 %
Negligible
The work ratio of a gas turbine plant is given by
(Net work output)/(Workdone by the turbine)
(Net work output)/(Heat supplied)
(Actual temperature drop)/(Isentropic temperature drop)
(Isentropic increase in temperature)/(Actual increase in temperature)
The property of a working substance which increases or decreases as the heat is supplied or removed in a reversible manner, is known as
Enthalpy
Internal energy
Entropy
External energy
Which of the following has the highest calorific value?
Peat
Lignite
Bituminous coal
Anthracite coal
For which material the Poisson's ratio is more than unity
Steel
Copper
Aluminium
None of the above
A hollow shaft of same cross-section area as compared to a solid shaft transmit
Same torque
Less torque
More torque
Unpredictable
Diesel cycle consists of following four processes
Two isothermal and two isentropic
Two isentropic and two constant volumes
Two isentropic, one constant volume and one constant pressure
Two isentropic and two constant pressures
Reversed joule cycle is called
Carnot cycle
Rankine cycle
Brayton cycle
Bell Coleman cycle
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 thermal efficiency of an ideal gas turbine plant is given by (where r = Pressure ratio)
rγ - 1
1 - rγ - 1
1 - (1/r) γ/γ - 1
1 - (1/r) γ - 1/ γ
A cylindrical section having no joint is known as
Joint less section
Homogeneous section
Perfect section
Seamless section
If a material expands freely due to heating it will develop
Thermal stresses
Tensile stress
Bending
No stress
Efficiency of a riveted joint is the ratio of its strength (max. load it can resist without failure) to the strength of the un-punched plate in
Tension
Compression
Bearing
Any one of the above
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
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
The relation between Young's modulus (E), shear modulus (C) and bulk modulus (K) is given by
E = 3K.C/(3K + C)
E = 6K.C/(3K + C)
E = 9K.C/(3K + C)
E = 12K.C/(3K + C)
The materials having same elastic properties in all directions are called
Ideal materials
Uniform materials
Isotropic materials
Piratical materials
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
The isothermal and adiabatic processes are regarded as
Reversible process
Irreversible process
Reversible or irreversible process
None of these
A process, in which the gas is heated or expanded in such a way that the product of its pressure and volume remains constant, is called
Isothermal process
Hyperbolic process
Adiabatic process
Polytropic process