The absolute pressure of air at the outlet of a compressor is called
Back pressure
Critical pressure
Discharge pressure
None of these
Correct Answer :
C. Discharge pressure
Related Questions
In an axial flow compressor, the ratio of pressure in the rotor blades to the pressure rise in the compressor in one stage is known as
Work factor
Slip factor
Degree of reaction
Pressure coefficient
The pressure ratio in gas turbines is of the order of
2 : 1
4 :1
61 : 1
9 : 1
The maximum delivery pressure in a rotary air compressor is
10 bar
20 bar
30 bar
50 bar
Ratio of indicated h.p. to shaft h.p. in known as
Compressor efficiency
Isothermal efficiency
Volumetric efficiency
Mechanical efficiency
If the flow of air through the compressor is perpendicular to its axis, then it is a
Reciprocating compressor
Centrifugal compressor
Axial flow compressor
Turbo compressor
Propulsive efficiency is defined as ratio of
Thrust power and fuel energy
Engine output and propulsive power
Propulsive power and fuel input
Thrust power and propulsive power
Separators in compressor installations are located
Before intercooler
After intercooler
After receiver
Between after-cooler and air receiver
With the decrease in compression ratio, the volumetric efficiency
Does not change
Increases
Decreases
First decrease and then increase
Out of the following, from where you will prefer to take intake for air compressor
From an air conditioned room maintained at 20°C
From outside atmosphere at 1°C
From coal yard side
From a side where cooling tower is located nearby
Pressure ratio in gas turbines is the ratio of
Compressor pressure ratio
Highest pressure to exhaust pressure
Inlet pressure to exhaust pressure
Pressures across the turbine
The air entry velocity m a rocket as compared to aircraft is
Same
More
Less
Zero
If p₁, is the pressure of air entering the L.P. cylinder and p₂ is the pressure of air leaving the L.P. cylinder (or intercooler pressure), then the ratio of cylinder diameters for a single acting, two stage reciprocating air compressor with complete intercooling is given by (where D₁ = Dia. of L.P. cylinder, and D₂ = Dia. of H.P. cylinder)
D₁/D₂ = p₁ p₂
D₁/D₂ = p₁/p₂
D₁/D₂ = p₂/p₁
None of these
Water gas is produced by
Carbonisation of coal
Passing steam over incandescent coke
Passing air and a large amount of steam over waste coal at about 65°C
Partial combustion of coal, eke, anthracite coal or charcoal in a mixed air steam blast
In a centrifugal compressor, the flow of air is ________ to the axis of compressor.
Parallel
Perpendicular
Inclined
None of these
Gas turbines for power generation are normally used
To supply base load requirements
To supply peak load requirements
To enable start thermal power plant
In emergency
Maximum work is done in compressing air when the compression is
Isothermal
Adiabatic
Polytropic
None of the above
In air compressors, free air delivery means the
Actual volume of the air delivered by the compressor when reduced to normal temperature and pressure conditions
Volume of air delivered by the compressor
Volume of air sucked by the compressor during its suction stroke
None of the above
Ratio of compression is the ratio of
Gauge discharge pressure to the gauge intake pressure
Absolute discharge pressure to the absolute intake pressure
Pressures at discharge and suction corresponding to same temperature
Stroke volume and clearance volume
The gas in cooling chamber of a closed cycle gas turbine is cooled at
Constant volume
Constant temperature
Constant pressure
None of these
The absolute pressure of air at the outlet of a compressor is called
Back pressure
Critical pressure
Discharge pressure
None of these
Rotary compressor is best suited for
Large quantity of air at high pressure
Small quantity of air at high pressure
Small quantity of air at low pressure
Large quantity of air at low pressure
Which of the following statement is correct relating to rocket engines?
The combustion chamber in a rocket engine is directly analogous to the reservoir of a supersonic wind tunnel
The stagnation conditions exist at the combustion chamber
The exit velocities of exhaust gases are much higher than those in jet engine
All of the above
The workdone on a compressor will be minimum if air is taken from
The atmosphere
A source at 0°C
A source of low temperature air
A source of high temperature air
In a double acting compressor, the air is compressed
In one cylinder
In two cylinders
In a single cylinder on both sides of the piston
In two cylinders on both sides of the piston
The overall isothermal efficiency of compressor is defined as the ratio of
Isothermal h.p. to the BHP of motor
Isothermal h.p. to adiabatic h.p.
Power to drive compressor to isothermal h.p.
Work to compress air isothermally to work for actual compression
The volumetric efficiency of compressor with increase in compression ratio will
Increase
Decrease
Remain same
May increase or decrease depending on clearance volume
In the axial flow gas turbine, the work ratio is the ratio of
Compressor work and turbine work
Output and input
Actual total head temperature drop to the isentropic total head drop from total head inlet to static head outlet
Actual compressor work and theoretical compressor work
To avoid moisture troubles, the compressed air main line should
Rise gradually towards the point of use
Drop gradually towards the point of use
Be laid vertically
Be laid exactly horizontally
The mean effective pressure of the compressor is the
Actual volume of the air delivered by the compressor when reduced to normal temperature and pressure conditions
Volume of air delivered by the compressor
Volume of air sucked by the compressor during its suction stroke
None of the above
Pick up the false statement
Gas turbine is a self starting unit
Gas turbine does not require huge quantity of water like steam plant
Exhaust losses in gas turbine are high due to large mass flow rate
Overall efficiency of gas turbine plant is lower than that of a reciprocating engine