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4

In a throttling process

A. Heat transfer takes place

B. Work is done by the expanding steam

C. Internal energy of steam changes

D. None of the above

Correct Answer :

D. None of the above


Related Questions

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4

For combustion of a fuel, following is essential

A. Correct fuel air ratio

B. Proper ignition temperature

C. O₂ to support combustion

D. All the three above

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4

Steam turbines are used for

A. Large marine propulsion

B. Electric power generation

C. Direct drive of fans, compressors, pumps

D. All of these

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4

In an ideal impulse turbine, the

A. Absolute velocity at the inlet of moving blade is equal to that at the outlet

B. Relative velocity at the inlet of the moving blade is equal to that at the outlet

C. Axial velocity at inlet is equal to that at the outlet

D. Whirl velocity at inlet is equal to that at the outlet

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4

Pick up the wrong statement about water tube boiler in comparison to fire tube boilers

A. Former occupies less space for same power

B. Rate of steam flow is more in former case

C. Former is used for high installed capacity

D. Chances of explosion are less in former case.

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4

The safety valve on boiler drum compared to safety valve on superheater is set at

A. Same value

B. Higher value

C. Lower value

D. Lower/higher depending on steam flow

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4

100% efficiency of a thermal cycle cannot be achieved because of

A. Frictional losses

B. It is not possible to achieve 0°K temperature

C. Leakage

D. Non availability of ideal substance

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4

Which of the following statement is correct for a compound steam engine?

A. The cost of the engine, for the same power and economy, is more than that of a simple steam engine.

B. The forces in the working parts are increased as the forces are distributed over more parts.

C. The ratio of expansion is reduced, thus reducing the length of stroke.

D. The temperature range per cylinder is increased, with corresponding increase in condensation.

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4

The feed check valve is used in order to

A. Regulate flow of boiler water

B. Check level of water in boiler drum

C. Recirculate unwanted feed water

D. Allow high pressure feed water to flow to drum and not allow reverse flow to take place

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4

The biggest size of thermal power unit operating in India is

A. 30 MW

B. 60 MW

C. 100 MW

D. 500 MW

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4

A stage, in reaction turbine, is represented by

A. Number of casing

B. Number of entries of steam

C. Number of exits of steam

D. Each row of blades

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4

In a boiler, the heat is lost

A. To dry flue gases

B. In moisture present in the fuel

C. To steam formed by combustion of hydrogen per kg of fuel

D. All of the above

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4

Blow off cock in a boiler is used to

A. Control the flow of steam from the boiler to the main pipe and to shut off the steam completely when required

B. Empty the boiler when required and to discharge the mud, scale or sediments which are accumulated at the bottom of the boiler

C. Put off fire in the furnace of the boiler when the level of water in the boiler falls to an unsafe limit

D. Increase the temperature of saturated steam without raising its pressure

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4

The effect of bleeding is that

A. It increases the thermodynamic efficiency of the turbine

B. Boiler is supplied with hot water

C. It decreases the power developed by the turbine

D. All of the above

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4

In a De-Laval nozzle expanding superheated steam from 10 bar to 0.1 bar, the pressure at the minimum cross-section (i. e. pressure at throat, p₂) will be

A. 3.3 bar

B. 5.46 bar

C. 8.2 bar

D. 9.9 bar

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4

The equivalent evaporation is defined as

A. The ratio of heat actually used in producing the steam to the heat liberated in the furnace

B. The amount of water evaporated or steam produced in kg per kg of fuel burnt

C. The amount of water evaporated from and at 100°C into dry and saturated steam

D. The evaporation of 15.653 kg of water per hour from and at 100°C

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4

The actual power generated in the engine cylinder is called

A. Indicated power

B. Brake power

C. Frictional power

D. None of these

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4

The clearance in the engine cylinder

A. Increases the mean effective pressure

B. Increases the workdone

C. Decreases the efficiency of the engine

D. All of these

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4

The radius of a dished head is taken approximately as

A. One fourth

B. Half

C. One

D. Two

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4

The reheat factor depends upon

A. Initial pressure and superheat

B. Exit pressure

C. Turbine stage efficiency

D. All of these

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4

Ultimate analysis of fuel is determination of percentage of

A. Carbon, hydrogen, nitrogen, sulphur, moisture

B. Fixed carbon, ash, volatile matter, moisture

C. Higher calorific value

D. Lower calorific value

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4

The increase in pressure

A. Lowers the boiling point of a liquid

B. Raises the boiling point of a liquid

C. Does not affects the boiling point of a liquid

D. Reduces its volume

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4

Vacuum for reciprocating steam engines compared to steam turbines is

A. More

B. Equal

C. Less

D. Could be more or less depending on the size of plant

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4

Natural water circulation, by convection in water tube boilers, with increase in pressure of boiler

A. Increases

B. Decreases

C. Remain unaffected

D. First increases and then decreases

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4

Adiabatic process is

A. Essentially an isentropic process

B. Non-heat transfer process

C. Reversible process

D. Constant temperature process

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4

The natural draught is produced by

A. Steam jet

B. Centrifugal fan

C. Chimney

D. Both (A) and (B)

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4

A turbine is said to have an axial discharge when the steam leaves the blade tip at _________ to the direction of the blade motion.

A. 60°

B. 90°

C. 180°

D. 270°

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4

Thermal equilibrium means that the flow of steam is

A. Isothermal

B. Isentropic

C. Hyperbolic

D. Polytropic

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4

Lancashire boiler has __________ internal flue tubes.

A. One

B. Two

C. Three

D. Four

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4

The dry saturated steam at very high pressure (150200 kg/cm²) when throttled to atmosphere will become

A. Wet

B. Superheated

C. Remain dry saturated

D. Dry

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4

At critical point, i.e. p = 225.65 kg/cm², the latent enthalpy of vaporisation is

A. Maximum

B. Minimum

C. Zero

D. Depends on temperature also