Chapter 19 Latest Board Questions

Question 1

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

Answer 1

B. H2 + H1

Question 2

At ordinary temperature what substance will behave as inert gas and will not react in the combustion process

Answer 2

A. Nitrogen

Question 3

Which of the following cycles is ideal for spark ignition in reciprocating engine

Answer 3

D. Otto cycle

Question 4

What is the relative humidity when the dew point and dry bulb temperature are equal

Answer 4

C. 100 %

Question 5

Reheating process is normally employed in steam plane when

Answer 5

C. Turbine undergoes excessive moisture

Question 6

Where does the final removal of water vapor in an absorption refrigeration system occur

Answer 6

D. Rectifier

Question 7

If the average temperature of liquid of power cycle during heat addition process is as high as possible, thermal efficiency of the cycle will

Answer 7

A. Increase

Question 8

What is the temperature if lubricant at which it will ignite thus limit its application

Answer 8

C. Flash point

Question 9

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

Answer 9

D. Refrigerating effects

Question 10

An air conditioning system in which water is chilled or cooled and which passes the evaporator coils

Answer 10

A. Chilled water system

Question 11

A multi stage refrigeration system which is realizable in using different refrigerants

Answer 11

B. Cascade

Question 12

Very large pipe diameter means a thicker wall and high cost. It also means

Answer 12

B. High pressure drop

Question 13

Aside from maintaining appropriate temperature for food cold storage, how is desiccation minimized or decreased

Answer 13

B. Maintain humidity ratio

Question 14

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

Answer 14

B. Carbon Monoxide

Question 15

As far as combustion chamber design is considered the maximum power output of a given engine can be increased by

Answer 15

C. Decreasing combustion chamber volume

Question 16

A water conservation device which employs both air and water is condensed a condenser and cooling tower combined into one is called

Answer 16

D. Evaporative condenser

Question 17

In order to perform efficiently, a power cycle must be communicated with the outside temperature of its surroundings and into one is called

Answer 17

B. Second law of Thermodynamics

Question 18

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

Answer 18

D. Convection

Question 19

When required, a regulator water valve in refrigerating system should be

Answer 19

D. In the water outlet

Question 20

When there is no work between the thermodynamic system and its surrounding, the quantity of net heat transfer is equal to

Answer 20

D. Total energy of a closed system

Question 21

In order to attain equilibrium in the condenser, the cooling tower range must be —– with respect to temperature rise in the condenser

Answer 21

B. Equal

Question 22

If ice will form in a solution if water and salt, then it is at a temperature called

Answer 22

B. Freezing point depression

Question 23

The flow of the convergent section if a nozzle is always subsonic. If the flow is subsonic then the mach number is

Answer 23

B. Less than unity

Question 24

One hundred twenty percent theoretical air was supplied for combustion. What is the equivalent excess equal to

Answer 24

A. 20%

Question 25

If Pi is the indicated horsepower and Pb is the indicated horsepower of a compressor, then what us mechanical efficiency, Em, equal to

Answer 25

B. Em = Pb/Pi

Question 26

What is the least number of compressor a multistage system that will use

Answer 26

B. Two

Question 27

The relation between the Fahrenheit absolute scale and the Celsius absolute scale is

Answer 27

A. R = 1.8 degree K

Question 28

The sum of the internal energy and the product of pressure and specific volume is known as the.

Answer 28

A. Enthalpy

Question 29

A refrigeration control that guards the compressor form overloads brought about by abruptly increases loads resulting from defrosting, warm products and others, is called

Answer 29

B. Suction hold back valve

Question 30

What does fossil fuel fired power plants release, which in turn produces the key ingredient in acid rain

Answer 30

B. Sulfur emission

Question 31

The fraction of the radiation energy incident on a surface which is absorbed by the surface is called

Answer 31

B. Absorptivity

Question 32

Which of the following power plants uses energy from uranium to produce electric power

Answer 32

C. Nuclear plant

Question 33

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

Answer 33

C. Dew point temperature

Question 34

The force when applied to a mass of one kilogram will give mass an acceleration of one meter per second for every second called

Answer 34

C. Newton

Question 35

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

Answer 35

A. Stagnation temperature

Question 36

The dew point temperature of the products of combustion in the saturation temperature that corresponds to the partial pressure of the - --- in the products

Answer 36

B. H2O

Question 37

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

Answer 37

D. Low water cut off

Question 38

Dry analysis is a fractional analysis of the products of combustion which does not include

Answer 38

A. Water vapor

Question 39

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

Answer 39

D. 4"

Question 40

One foot water is equal to

Answer 40

D. 62.43 lb/ft^2

Question 41

The freezing point of R -22 is

Answer 41

C. -256 degree Fahrenheit

Question 42

Which of the following is a type of evaporator

Answer 42

A. Shell and tube condenser

Question 43

For Brayton cycle, the result of regeneration is

Answer 43

A. Increase in thermal efficiency

Question 44

If the pressure exerted on a liquid is higher than the saturation corresponding to its temperature, the liquid is a

Answer 44

B. Subcooled liquid

Question 45

In a power driven pump, each piston stroke is displaced by 360 degrees divided the

Answer 45

D. Numbers of cylinders

Question 46

If the air is compressed without discarding heat, then what do you call this kind of compression

Answer 46

C. Adiabatic

Question 47

If a gas posses internal energy, then it is due to its

Answer 47

D. Molecular motion

Question 48

The pressure of ammonia was detected in brine solution. How can ammonia be removed

Answer 48

B. Heat the brine to a high temperature enough to free the ammonia

Question 49

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

Answer 49

C. Cavitation

Question 50

What does a negative Joule Thompson coefficient means during a throttling process

Answer 50

C. Fluid temperature rises

Question 51

For the steam power plants, increasing the operating pressure of the boiler will

Answer 51

A. Increase thermal efficiency

Question 52

The ratio of the average load to that of the rated capacity of a plant is called

Answer 52

D. Capacity factor

Question 53

What is the method used to evaluate all welds performed on pressure parts of boiler tube materials

Answer 53

D. Radiographic test

Question 54

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

Answer 54

C. Equal

Question 55

What is the effect on saturated temperature if the pressure of the fluid is decreased

Answer 55

B. Saturation temperature decreases

Question 56

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.

Answer 56

D. r = V3 / V2

Question 57

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

Answer 57

B. Higher for the superheated cycle

Question 58

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

Answer 58

D. Safety valve

Question 59

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

Answer 59

Q is directly proportional to the ratio of D

Question 60

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

Answer 60

D. (Wt - Wc) / Q

Question 61

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

Answer 61

C. N x S

Question 62

What is the pressure present inside the casing of an impulse turbine

Answer 62

B. Atmospheric pressure

Question 63

In order to remove the fly ashes from the flue gas, which of the following must a power plant be equipped with

Answer 63

C. Electrostatic precipitator

Question 64

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

Answer 64

C. Ht = Hs + Hp + Hf

Question 65

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

Answer 65

D. Bleed off

Question 66

What process is employed when the turbine steam power plants experience excessive moisture

Answer 66

A. Reheating

Question 67

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

Answer 67

C. Kaplan turbine

Question 68

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

Answer 68

B. Et / Er

Question 69

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

Answer 69

B. e = W/H

Question 70

Which of the following is converted to mechanical energy by a water

Answer 70

C. Potential energy

Question 71

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

Answer 71

C. Available NPSH greater than required NPSH

Question 72

What type of fuel is used with stationary power plants where gas is available by pipeline

Answer 72

A. Gaseous fuels

Question 73

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

Answer 73

B. Wb is less than Wi

Question 74

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

Answer 74

B. Critical pressure

Question 75

What is the significance of a high dielectric strength of lubricating oil

Answer 75

B. Oil is contaminant free

Question 76

What is the significance of a high dielectric strength of lubricating oil

Answer 76

B. Oil is contaminant free

Question 77

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

Answer 77

D. Greater for a superheated cycle

Question 78

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:

Answer 78

D. Below its dew point temperature

Question 79

What does the enthalpy measure in a substance

Answer 79

B. Its heat content

Question 80

Pneumatic tools are powered by

Answer 80

B. Air

Question 81

The pump will not activate if the available Net Positive Suction Head (NPSH) is

Answer 81

C. Equal or greater than the required NPSH

Question 82

A water tube condenser has a total of 60 tubes. If these are two passes, then compute the number of tubes per pass

Answer 82

B. 15

Question 83

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

Answer 83

C. 1 - Ev

Question 84

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

Answer 84

D. Hp is directly proportional to the cube of the ratio of S

Question 85

What is likely to occur when sections of the impeller of a centrifugal pump are handling vapor and other sections are handling liquid

Answer 85

D. Complete failure to operate

Question 86

When vapor compression takes place on one side of the piston and one during one revolution of the crankshaft, then the compressor is

Answer 86

D. Single acting

Question 87

In Stirling and Erickson Cycles, the efficiency can be increased by

Answer 87

C. Regeneration

Question 88

Which of the following is used to control refrigeration compressor capacity

Answer 88

D. Unloader

Question 89

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

Answer 89

D. Hs / HT

Question 90

Based on the PSME Code, what should be provided in each stream outlets if two or more boilers will be connected in parallel

Answer 90

B. Non return and shut off valves

Question 91

The diesel cycle is the ideal cycle for a

Answer 91

C. Compression ignition engine

Question 92

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

Answer 92

D. Lower efficiency

Question 93

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

Answer 93

D. AUD

Question 94

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

Answer 94

D. m (r x H)

Question 95

When an electric motor nameplate indicates a " 100 kw electric motor" then what does a 100 kw rating refers to

Answer 95

D. Mechanical power output

Question 96

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

Answer 96

C. 1/4 H

Question 97

The ratio of the average load during a certain time to peak the load occurring during the same period of time is called:

Answer 97

C. Load factor

Question 98

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

Answer 98

C. 20 to 24 degrees C

Question 99

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

Answer 99

C. (R x H) / e

Question 100

There are three basic boiler types, namely

Answer 100

B. Cast iron, fire tube, and water tubes

Question 101

The amount of heat necessary to bring up the temperature of a unit mass of a substance through a unit degree is called

Answer 101

D. Specific heat

Question 102

What is the specific gravity of an oil which has a Baume reading g of 28 degrees F

Answer 102

C. 0.886

Question 103

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.

Answer 103

C. L = C x F

Question 104

Based on the PSME code, what should be the humidity of air to be used for comfort cooling

Answer 104

B. 50-60% relative humidity

Question 105

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

Answer 105

B. Fluid friction