Chapter 19 Latest Board Questions Flashcards
A pump with capacity Q1 and head H1 is connected in series with another pump with capacity Q2 and head H2. What is the head developed if Q2 is less than Q1
B. H2 + H1
At ordinary temperature what substance will behave as inert gas and will not react in the combustion process
A. Nitrogen
Which of the following cycles is ideal for spark ignition in reciprocating engine
D. Otto cycle
What is the relative humidity when the dew point and dry bulb temperature are equal
C. 100 %
Reheating process is normally employed in steam plane when
C. Turbine undergoes excessive moisture
Where does the final removal of water vapor in an absorption refrigeration system occur
D. Rectifier
If the average temperature of liquid of power cycle during heat addition process is as high as possible, thermal efficiency of the cycle will
A. Increase
What is the temperature if lubricant at which it will ignite thus limit its application
C. Flash point
What is the heat that is removed from the space to be cooled, which is the same as the heat absorbed by the cooling coils
D. Refrigerating effects
An air conditioning system in which water is chilled or cooled and which passes the evaporator coils
A. Chilled water system
A multi stage refrigeration system which is realizable in using different refrigerants
B. Cascade
Very large pipe diameter means a thicker wall and high cost. It also means
B. High pressure drop
Aside from maintaining appropriate temperature for food cold storage, how is desiccation minimized or decreased
B. Maintain humidity ratio
During combustion process, only limited air is supplied and not enough to supply two molecule of oxygen per one molecule of carbon, then the product is
B. Carbon Monoxide
As far as combustion chamber design is considered the maximum power output of a given engine can be increased by
C. Decreasing combustion chamber volume
A water conservation device which employs both air and water is condensed a condenser and cooling tower combined into one is called
D. Evaporative condenser
In order to perform efficiently, a power cycle must be communicated with the outside temperature of its surroundings and into one is called
B. Second law of Thermodynamics
Water is heated in a container, it expands and becomes less dense and lighter. It rises up the container because of its reduced density and replaced by cooler air. As this process continues, the heat is transferred and disturbed all throughout. What is this mode of heat transfer called
D. Convection
When required, a regulator water valve in refrigerating system should be
D. In the water outlet
When there is no work between the thermodynamic system and its surrounding, the quantity of net heat transfer is equal to
D. Total energy of a closed system
In order to attain equilibrium in the condenser, the cooling tower range must be —– with respect to temperature rise in the condenser
B. Equal
If ice will form in a solution if water and salt, then it is at a temperature called
B. Freezing point depression
The flow of the convergent section if a nozzle is always subsonic. If the flow is subsonic then the mach number is
B. Less than unity
One hundred twenty percent theoretical air was supplied for combustion. What is the equivalent excess equal to
A. 20%
If Pi is the indicated horsepower and Pb is the indicated horsepower of a compressor, then what us mechanical efficiency, Em, equal to
B. Em = Pb/Pi
What is the least number of compressor a multistage system that will use
B. Two
The relation between the Fahrenheit absolute scale and the Celsius absolute scale is
A. R = 1.8 degree K
The sum of the internal energy and the product of pressure and specific volume is known as the.
A. Enthalpy
A refrigeration control that guards the compressor form overloads brought about by abruptly increases loads resulting from defrosting, warm products and others, is called
B. Suction hold back valve
What does fossil fuel fired power plants release, which in turn produces the key ingredient in acid rain
B. Sulfur emission
The fraction of the radiation energy incident on a surface which is absorbed by the surface is called
B. Absorptivity
Which of the following power plants uses energy from uranium to produce electric power
C. Nuclear plant
Ice cubes added to a glass of water and stirred. Moisture starts to form on the outer surface of the glass. At this point, what is the temperature at the outer surface called
C. Dew point temperature
The force when applied to a mass of one kilogram will give mass an acceleration of one meter per second for every second called
C. Newton
The kinetic energy of a moving fluid is used to isentropically compressed the fluid to state of zero velocity. The temperature of a moving fluid at the state zero velocity is called
A. Stagnation temperature
The dew point temperature of the products of combustion in the saturation temperature that corresponds to the partial pressure of the - — in the products
B. H2O
What do we call a device that is used to boiler operation that will stop the burner or at least send a signal to the operator if the water drops to a low level that is no longer safe
D. Low water cut off
Dry analysis is a fractional analysis of the products of combustion which does not include
A. Water vapor
The size of a reciprocating pump is stamped on the builder’s plate 3” x 4” x 6”. The diameter of the liquid cylinder is
D. 4”
One foot water is equal to
D. 62.43 lb/ft^2
The freezing point of R -22 is
C. -256 degree Fahrenheit
Which of the following is a type of evaporator
A. Shell and tube condenser
For Brayton cycle, the result of regeneration is
A. Increase in thermal efficiency
If the pressure exerted on a liquid is higher than the saturation corresponding to its temperature, the liquid is a
B. Subcooled liquid
In a power driven pump, each piston stroke is displaced by 360 degrees divided the
D. Numbers of cylinders
If the air is compressed without discarding heat, then what do you call this kind of compression
C. Adiabatic
If a gas posses internal energy, then it is due to its
D. Molecular motion
The pressure of ammonia was detected in brine solution. How can ammonia be removed
B. Heat the brine to a high temperature enough to free the ammonia
What will happen when the pressure at any point inside a centrifugal pump goes below the vapor pressure corresponding to the temperature of the liquid
C. Cavitation
What does a negative Joule Thompson coefficient means during a throttling process
C. Fluid temperature rises
For the steam power plants, increasing the operating pressure of the boiler will
A. Increase thermal efficiency
The ratio of the average load to that of the rated capacity of a plant is called
D. Capacity factor
What is the method used to evaluate all welds performed on pressure parts of boiler tube materials
D. Radiographic test
If the pressure is disregarded in the various other components of a steam of gas power plants, the pressure rise in the pump or compressor is —- to the pressure drop in the turbine
C. Equal
What is the effect on saturated temperature if the pressure of the fluid is decreased
B. Saturation temperature decreases
If V3 is the cylinder volume after the combustion process of a Diesel cycle and V2 is its cylinder volume before combustion, then calculate the cut off ratio, r.
D. r = V3 / V2
Compare the temperature of the discharge vapor refrigerant leaving the compressor for a superheated cycle and the saturated cycle, for the same condensing temperature and pressure
B. Higher for the superheated cycle
A valve that releases steam from the boiler by opening at s pre-determined pressure in order to keep the steam pressure from rising more than the pressure from which the valve is set is called a
D. Safety valve
What is the relationship of the capacity of a centrifugal pump, Q, to impeller diameter, D, when there are two impeller diameters in the same pump
Q is directly proportional to the ratio of D
If Wt is the turbine shaft work if a gas turbine unit, Wc is its compressor shaft work and Q is the heat supplied in duel, then determine its thermal efficiency
D. (Wt - Wc) / Q
The schedule of a pipe, N, indicates the thickness of the pipe wall. If allowable stress of the pipe is S, then what is the internal pressure equal to
C. N x S
What is the pressure present inside the casing of an impulse turbine
B. Atmospheric pressure
In order to remove the fly ashes from the flue gas, which of the following must a power plant be equipped with
C. Electrostatic precipitator
If Hs is the total suction head of a pump, Hp is its suction surface pressure, and Hf is its suction friction head, then calculate the total suction head Ht
C. Ht = Hs + Hp + Hf
The constant spending of certain percentage of circulated water in a cooling tower in order to prevent accumulation of dissolved mineral solids and other impurities in the condenser water is called
D. Bleed off
What process is employed when the turbine steam power plants experience excessive moisture
A. Reheating
A company is interested to produce a water turbine wherein only little energy is required or necessary because the guide vanes are to be controlled. The turbine must be a
C. Kaplan turbine
If Et is the total net energy generated by a plant in a certain period of time and Er is the rated energy capacity of the plant during the same period of time, then what is the plant operating factor
B. Et / Er
If W is the work output of a heat engine and H is the total heat input of an engine, then determine its thermal efficiency, e
B. e = W/H
Which of the following is converted to mechanical energy by a water
C. Potential energy
What must be the value of the available Net Positive Suction Head (NPSH) of a centrifugal pump compared to its required NPSH to avoid losing priming
C. Available NPSH greater than required NPSH
What type of fuel is used with stationary power plants where gas is available by pipeline
A. Gaseous fuels
Wb is shaft work of an engine and Wi is the indicated work of an engine. If mechanical friction is present in the engine mechanism, then
B. Wb is less than Wi
What is the saturation pressure at the critical temperature, or the lowest pressure in which a substance can be in the liquid state at its critical pressure
B. Critical pressure
What is the significance of a high dielectric strength of lubricating oil
B. Oil is contaminant free
What is the significance of a high dielectric strength of lubricating oil
B. Oil is contaminant free
Compare the refrigerating effect per unit mass of refrigerant circulated for a superheated cycle that produces useful cooling and a saturated cycle, for the same vaporizing and condensing temperature
D. Greater for a superheated cycle
It is important to take some moisture from the air to dehumidify it if the relative humidity reaches high levels. To do this, it requires cooling the air:
D. Below its dew point temperature
What does the enthalpy measure in a substance
B. Its heat content
Pneumatic tools are powered by
B. Air
The pump will not activate if the available Net Positive Suction Head (NPSH) is
C. Equal or greater than the required NPSH
A water tube condenser has a total of 60 tubes. If these are two passes, then compute the number of tubes per pass
B. 15
If Ev is the volumetric efficiency of a reciprocating pump, then determine SLIP which represents all losses of capacity given in percentage of the displacement
C. 1 - Ev
What is the relationship of the horsepower of a centrifugal pump, Hp, to the impeller speed, S, if the pump is at two different rotative speeds
D. Hp is directly proportional to the cube of the ratio of S
What is likely to occur when sections of the impeller of a centrifugal pump are handling vapor and other sections are handling liquid
D. Complete failure to operate
When vapor compression takes place on one side of the piston and one during one revolution of the crankshaft, then the compressor is
D. Single acting
In Stirling and Erickson Cycles, the efficiency can be increased by
C. Regeneration
Which of the following is used to control refrigeration compressor capacity
D. Unloader
During a cooling and dehumidifying process, sensible and latent heats are removed in the cooling coil. If Hs is the sensible heat and Ht is the total heat transferred, then determine the coil sensible factor
D. Hs / HT
Based on the PSME Code, what should be provided in each stream outlets if two or more boilers will be connected in parallel
B. Non return and shut off valves
The diesel cycle is the ideal cycle for a
C. Compression ignition engine
If a Carnot cycle is at the same maximum and minimum temperatures as a Rankine cycle, then how would you compare the efficiency of a Rankine cycle to that of the Carnot Cycle
D. Lower efficiency
Compute the wall gain load of a load storage room when A is outside surface area of the wall, D is the temperature differential across the wall, and U is the overall coefficient of heat transmission
D. AUD
If m is the mass of dry air and H is the specific enthalpy of the water vapor in air and r is the humidity ratio, then determine the latent heat of any dry air
D. m (r x H)
When an electric motor nameplate indicates a “ 100 kw electric motor” then what does a 100 kw rating refers to
D. Mechanical power output
For a hydraulic power to be transmitted at its maximum what should be the value of loss of head due to friction if H is the total available head
C. 1/4 H
The ratio of the average load during a certain time to peak the load occurring during the same period of time is called:
C. Load factor
Based on the PSME Code, what should be the effective temperature of the air to be maintained for comfort cooling at an air movement from 0.0761 to 0.127 meter per second
C. 20 to 24 degrees C
If R is the delivery rate of a pump, H is the total pumping head and e is the efficiency of the pump, then compute the power required to drive the pump
C. (R x H) / e
There are three basic boiler types, namely
B. Cast iron, fire tube, and water tubes
The amount of heat necessary to bring up the temperature of a unit mass of a substance through a unit degree is called
D. Specific heat
What is the specific gravity of an oil which has a Baume reading g of 28 degrees F
C. 0.886
If C is the capacity of the compressor in a refrigeration system and F is the heat rejection factor, then calculate the condenser load, L.
C. L = C x F
Based on the PSME code, what should be the humidity of air to be used for comfort cooling
B. 50-60% relative humidity
What is the cause of pressure drop in the boiler, condenser, and the pipings between different components? Because of this drop, steam leaving the boiler is at lower pressure
B. Fluid friction
