Description : In a Rankine cycle, regeneration results in higher efficiency because (a) Pressure inside the boiler increases [GATE-2003] (b) Heat is added before steam enters the low pressure turbine (c) ... temperature of heat addition in the boiler increases (d) Total work delivered by the turbine increases
Last Answer : (c) Average temperature of heat addition in the boiler increases
Description : The efficiency of superheat Rankine cycle is higher than that of simple Rankine cycle because [GATE-2002] (a) The enthalpy of main steam is higher for superheat cycle (b) The mean temperature of heat ... temperature of steam in the condenser is high (d) The quality of stem in the condenser is low
Last Answer : (b) The mean temperature of heat addition is higher for superheat cycle
Description : In a Rankine cycle, with the maximum steam temperature being fixed from metallurgical considerations, as the boiler pressure increases (a) The condenser load will increase [IES-1997] (b) The ... The quality of turbine exhaust will increase (d) The quality of turbine exhaust will remain unchanged
Last Answer : (b) The quality of turbine exhaust will decrease
Description : Consider the following processes: [IES-1999] 1. Constant pressure heat addition. 2. Adiabatic compression. 3. Adiabatic expansion. 4. Constant pressure heat rejection. The correct sequence of these processes in Rankine cycle is: (a) 1, 2, 3, 4 (b) 2, 1, 4, 3 (c) 2, 1, 3, 4 (d) 1, 2, 4, 3
Last Answer : (c) 2, 1, 3, 4
Description : In steam and other vapour cycles, the process of removing noncondensable is called [GATE-1992] (a) Scavenging process (b) Deaeration process (c) Exhaust process (d) Condensation process
Last Answer : (b) Deaeration process
Description : During which of following process does heat rejection take place in Carnot vapour cycle? [IES-1992] (a) Constant volume (b) constant pressure (c) Constant temperature (d) constant entropy
Last Answer : (c) Constant temperature
Description : The correct sequence of factors in order of deceasing importance for location of a thermal power plant is [IAS-2001] (a) load, coal, water (b) coal, water, load (c) Water, load, coal (d) water, coal, load
Last Answer : (b) coal, water, load
Description : In thermal power plants, coal is transferred from bunker to the other places by [IES-1992] (a) Hoists (b) conveyors (c) cranes (d) lifts
Last Answer : (b) conveyors
Description : A thermoelectric engine which consists of two dissimilar electric conductors connected at two junctions maintained at different temperatures, converts (a) Electric energy into heat energy [IES-2006] (b ... energy (c) Mechanical work into electric energy (d) Electric energy into mechanical work
Last Answer : (b) Heat energy into electric energy
Description : Pick out the wrong statement. (A) In process heat exchangers, saturated steam is preferred over the superheated steam (B) The maximum is the emissive power of a surface at a temperature T1 ... under natural convection conditions, the velocity profile in air, normal to the plate, exhibits a maximum
Last Answer : (B) The maximum is the emissive power of a surface at a temperature T1 occurs at a wavelength of λ1 . If the surface temperature is halved, the maximum in the emissive power would occur at a wavelength of 0.5 λ1
Description : Which of the following quantities has the GREATEST influence on the overall efficiency of a conventional (Rankine cycle) electric generating station burning fossil fuels? w) steam temperature at the steam turbine ... pressure at the steam turbine inlet z) pounds of ash and sulfur per pound of fuel
Last Answer : ANSWER: W -- STEAM TEMPERATURE AT THE STEAM TURBINE INLET
Description : The thermodynamic difference between a Rankine cycle working with saturated steam and the Carnot cycle is that (a) carnot cycle can't work with saturated steam (b) heat is supplied to water at temperature ... heat at two places (d) rankine cycle is hypothetical (e) none of the above.
Last Answer : Answer : b
Description : What is the highest efficiency of heat engine operating between the two thermal energy reservoirs at temperature limits? A. Ericson efficiency B. Otto efficiency C. Carnot efficiency D. Stirling efficiency
Last Answer : Carnot efficiency
Description : Coolant present in the primary circuit of a pressurised water reactor is high pressure (A) Sub cooled water (B) Saturated water (C) Superheated steam (D) Saturated steam
Last Answer : (B) Saturated wate
Description : Saturated steam at a pressure of 25 kg/cm2is throttled to attain 5 kg/cm2. Then the outcoming steam will be (A) Wet (B) Saturated (C) Superheated (D) None of these
Last Answer : C) Superheated
Description : Dry saturated steam can be converted into superheated steam by (A) Increasing its cross-sectional area of flow (B) Passing it through a pressure reducing valve (C) Forcing it downwards through a vertical tube (D) None of these
Last Answer : (B) Passing it through a pressure reducing valve
Description : __________________ is a vapor having a temperature higher than the saturation temperature corresponding to the existing pressure. a) Vapor b) Saturated Vapor c) Superheated Vapor d) Wet Vapor
Last Answer : Superheated Vapor
Description : ___________________ is a vapor at the saturation conditions (saturation temperature and saturation pressure). a) Vapor b) Saturated Vapor c) Superheated Vapor d) Wet Vapor
Last Answer : Saturated Vapor
Description : For which of the following substances, the gas laws can be used with minimum error (a) dry steam (b) wet steam (c) saturated steam (d) superheated steam (e) steam at atmospheric pressure.
Last Answer : Answer : d
Description : _________________ is the name given to a gaseous phase that is in contact with the liquid phase, or that is in the vicinity of a state where some of it might be condensed. a) Vapor b) Saturated Vapor c) Superheated Vapor d) Wet Vapor
Last Answer : Vapor
Description : Rankine cycle efficiency in a good steam power station may be in the range between........ a.15% - 20% b.35% - 40% c.50% - 60% d.90% - 95%
Last Answer : b.35% - 40%
Description : The rankine cycle efficiency of steam power plant is (1) 60-80% (3) 30-45% (2) 45-80% (4) 20-30%
Last Answer : The rankine cycle efficiency of steam power plant is 30-45%
Description : The efficiency of Diesel cycle depends upon A. temperature limits B. pressure ratio C. compression ratio D. cut-off ratio and compression ratio
Last Answer : Answer: D
Description : The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is (A) More (B) Less (C) Some (D) Either more or less; depends on the nature of vapor
Last Answer : (C) Some
Description : Steam undergoes isentropic expansion in a turbine from 5000 kPa and 400°C (entropy = 6.65 kJ/kg K) to 150 kPa) (entropy of saturated liquid = 1.4336 kJ/kg. K, entropy of saturated vapour = 7.2234 ... vapour with quality of 0.9 (C) Saturated vapour (D) Partially condensed vapour with quality of 0.1
Last Answer : (A) Superheated vapour
Description : Adiabatic compression of a saturated water vapour makes it (A) Supersaturated (B) Superheated (C) Both (A) and (B) (D) Neither (A) nor (B)
Last Answer : B) Superheated
Description : Which of the following approaches the ideal gas behaviour most closely? (A) Wet steam (B) Saturated steam (C) Superheated steam (D) Saturated water
Last Answer : Option C
Description : What type of steam is generated by evaporator tube of Lamont boiler ? a. Saturated steam b. Unsaturated steam c. Superheated steam d. Flash steam
Last Answer : a. Saturated steam
Description : _________________ is a combination of saturated vapor and saturated liquid. a) Vapor b) Saturated Vapor c) Superheated Vapor d) Wet Vapor
Last Answer : Wet Vapor
Description : Which is NOT a correct statement? A. A superheated vapor will not condense when small amount of heat re removed B. An ideal gas is a gas that is not a superheated vapor C. A saturated ... absorb as much heat as it can without vaporizing D. Water at 1 atm and room temperature is subcooled
Last Answer : An ideal gas is a gas that is not a superheated vapor
Description : A vapor that is not about to condense is called _____ vapor. A. Saturated B. Compressed or subcooled C. Superheated D. Unsaturated
Last Answer : Superheated
Description : A vapor that is about to condense is called ______ vapor. A. Saturated B. Compressed or subcooled C. Superheated D. Unsaturated
Last Answer : Saturated
Description : A liquid that is about to vaporize is called ______ liquid. A. Saturated B. Compressed or subcooled C. Superheated D. Unsaturated
Description : When water exists in the liquid phase and is not about to vaporize, it is considered as _____liquid. A. Saturated B. Compressed or subcooled C. Superheated D. Unsaturated
Last Answer : Compressed or subcooled
Description : For which of the following substances, the internal energy and enthalpy are the functions of temperature only (a) any gas (b) saturated steam (c) water (d) perfect gas (e) superheated steam.
Description : Saturated steam at 1 atm is discharged from a turbine at 1200 kg/h. Superheated steam at 300 0C and 1 atm is needed as a feed to a heat exchanger. To produce it, the turbine discharge ... amount of superheated steam at 300 0C produced and the volumetric flow rate of the 400 0C steam.
Last Answer : Solution 1. Mass balance of water 1200 + m1 = m2 ………………………………………… (1) …………………….1 mark 2. Energy balance (1200 kg/h)(2676 kJ/kg) + m1(3278 kJ/kg)
Description : Represent generation of steam on H-S diagram. Show constant dryness fraction lines, constant temperature lines, saturated line and superheated region on the same.
Last Answer : Represent generation of steam on H-S diagram. Show constant dryness fraction lines, constant temperature lines, saturated line and superheated region on the same.
Description : What is the purpose of each of the 'signal conditioners' (6000F085 / AH170 / F125) shown in the illustration? EL-0094 A. Convert the varying signal from its particular sensor and deliver a ... the 'setpoint module' in order to keep the pressure or temperature at its sensor at set limits.
Last Answer : Answer: A
Description : If both Stirling and Carnot cycles operate within the same temperature limits, then efficiency of Stirling cycle as compared to Carnot cycle (a) more (b) less (c) equal (d) depends on other factors (e) none of the above.
Last Answer : Answer : c
Description : Heat is added at constant pressure in an ideal __________ cycle. (A) Stirling (B) Brayton (C) Rankine (D) Both (B) and (C)
Last Answer : (D) Both (B) and (C)
Description : In thermodynamics, a throttling process, also called a _________, is a type of isenthalpic process where a liquid or gas is cooled as it passes from a higher pressure state to a lower pressure state. a. Rankine Process b. Carnot Cycle c. Joule-Thomson process d. Refrigeration process
Last Answer : Joule-Thomson process
Description : Explain Reheat cycle?
Last Answer : If the dryness fraction of steam leaving the turbine is less than 0.88, then, corrosion and erosion of turbine blades occur. To avoid this situation, reheat is used. In the reheat cycle, the ... turbine first, and then it is reheated. The reheated steam is again expanded in. the LP turbine.
Description : Explain Reheat Cycle?
Description : Apart from feed heating, what should a plant have to obtain a gain in thermal efficiency? a) Lubrication b) Differential heating c) Reheating cycles d) Regenerative cycles
Last Answer : c) Reheating cycles
Description : Which statement of the second law of thermodynamics states that no heat engine can have a thermal efficiency of 100 percent? A. Kelvin-Planck statement B. Clausius statement C. Kevin statement D. Rankine statement
Last Answer : Kelvin-Planck statement
Description : Which of the following cycles has maximum efficiency (a) Rankine (b) Stirling (c) Carnot (d) Brayton (e) Joule.
Description : In vapour compression cycle the condition of refrigerant is superheated vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) beforeentering the expansion valve
Last Answer : Ans: b
Description : What refers to the pressure at which a pure substance changes phase at a given temperature? A. Equilibrium pressure B. Saturation pressure C. Superheated pressure D. Subcooled pressure
Last Answer : Saturation pressure
Description : What refers to the temperature at which a pure substance changes phase at a given pressure? A. Equilibrium temperature B. Saturation temperature C. Superheated temperature D. Subcooled temperature
Last Answer : Saturation temperature
Description : 1 kg of a saturated aqueous solution of a highly soluble component A at 60°C is cooled to 25°C. The solubility limits of A are (0.6 kgA/kg water) at 60°C and (0.2 kgA/kg water) at 25°C. The amount in kg of the crystals formed is: (A) 0.4 (B) 0.25 (C) 0.2 (D) 0.175
Last Answer : (C) 0.2