High air-fuel ratio in gas turbines
Increases power output
Improves thermal efficiency
Reduces exhaust temperature
Do not damage turbine blades
Correct Answer :
C. Reduces exhaust temperature
Related Questions
Formula based on IS codes is based on
Straight line formula
Eulers formula
Rankines formula
Secant formula
High air-fuel ratio in gas turbines
Increases power output
Improves thermal efficiency
Reduces exhaust temperature
Do not damage turbine blades
The strain energy stored in a solid circular shaft in torsion, subjected to shear stress (τ), is: (Where, G = Modulus of rigidity for the shaft material)
τ²/ 2G × Volume of shaft
τ/ 2G × Volume of shaft
τ²/ 4G × Volume of shaft
τ/ 4G × Volume of shaft
The specific heat of water is
1.817
2512
4.187
None of these
Principal planes are planes having
Maximum shear stress
No shear stress
Minimum shear stress
None of the above
Resilience of a material is considered when it is subjected to
Frequent heat treatment
Fatigue
Creep
Shock loading
The gas turbine cycle with regenerator improves
Thermal efficiency
Work ratio
Avoids pollution
None of these
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
The process is adiabatic, if the value of n in the equation pvn = C, is
0
1
γ
∝
The amount of heat generated per kg of fuel is known as
Calorific value
Heat energy
Lower calorific value
Higher calorific value
Carnot cycle has maximum efficiency for
Petrol engine
Diesel engine
Reversible engine
Irreversible engine
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 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]
The bending moment at a point on a beam is the algebraic ________ of all the moments on either side of the point.
Sum
Difference
Multiplication
None of the above
The efficiency and work ratio of a simple gas turbine cycle are
Very low
Low
High
Very high
The efficiency of Ericsson cycle is __________ Carnot cycle.
Greater than
Less than
Equal to
None of these
The ideal efficiency of a Brayton cycle with regeneration, with increase in pressure ratio will
Increase
Decrease
Remain unchanged
Increase/decrease depending on application
Coke is produced
When coal is first dried and then crushed to a fine powder by pulverising machine
From the finely ground coal by moulding under pressure with or without a binding material
When coal is strongly heated continuously for 42 to 48 hours in the absence of air in a closed vessel
By heating wood with a limited supply of air to a temperature not less than 280°C
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
Modulus of rigidity may be defined as the ratio of
Linear stress to lateral strain
Lateral strain to linear strain
Linear stress to linear strain
Shear stress to shear strain
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
The ratio of lateral strain to the linear strain within elastic limit is known as
Young's modulus
Bulk modulus
Modulus of rigidity
Poisson's ratio
Which of the following cycles has maximum efficiency?
Rankine
Stirling
Carnot
Brayton
The extremeties of any diameter on Mohr's circle represent
Principal stresses
Normal stresses on planes at 45°
Shear stresses on planes at 45°
Normal and shear stresses on a plane
Which of the following is an irreversible cycle?
Carnot
Stirling
Ericsson
None of the above
The value of 1 mm of Hg is equal to
1.333 N/m2
13.33 N/m2
133.3 N/m2
1333 N/m2
In a free expansion process,
W1 - 2 = 0
Q1 - 2 = 0
dU = 0
All of these
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
The thermodynamic difference between a Rankine cycle working with saturated steam and the Carnot cycle is that
Carnot cycle can't work with saturated steam
Heat is supplied to water at temperature below the maximum temperature of the cycle
A Rankine cycle receives heat at two places
Rankine cycle is hypothetical
The mass of excess air supplied is equal to
(23/100) × Mass of excess carbon
(23/100) × Mass of excess oxygen
(100/23) × Mass of excess carbon
(100/23) × Mass of excess oxygen