📝 [PIPE] QB ID: 1517081204 | Advanced Coaching Series | Set 01 – Elements

When air is saturated, the wet bulb depression is

In a window air conditioning unit which of the following is usually done by the owner?

Fan motors in air conditioning units usually have

Which of the following capacitors that can usually be found in an air conditioning unit?

Which of the following troubles commonly occurs inside an air conditioning unit?

The motor condition of an air conditioning unit can be checked with

An air conditioning system wherein the entire systems are mounted in the cabinet

The use of water to carry heat occupied spaces

The method of cooling which primarily used where ambient air temperatures are high and relative humidity is used

The other name for Swamp Cooling is

Evaporative condenser is used to cool

A method of cooling which uses water as refrigerant. Pressure on the water surface is reduced to lower its boiling temperature.

Palladium Chloride may be used to measure the presence of

The amount of CO can be determined by the color of Palladium Chloride. An amount of 30 ppm to 70 ppm will cause

The term used to express the amount moisture in a given sample of air. It is compared with the amount of moisture in a given sample of air

How should the window type air conditioning unit be placed?

A dehumidifier is usually a small hermitic refrigerating system. It has both a condenser and an evaporator. Many older systems use R-12 or R-500. The newer units use:

The normal cut-out setting of a window unit thermostat is between:

Thermostat are used with most window units. They have differentials which vary between

In an air conditioning unit, the thermostat fails. The unit did not start. How do you test the operation of the thermostat?

Which of the following dehumidifier is often used to reheat the air after moisture is removed?

Which of the following refrigerant is added sometimes to other refrigerant to improve oil circulation?

A refrigeration that deals with producing temperature of -157 °C or lower.

Measurement of a device’s ability to remove atmospheric air from test air.

A liquid mixture having constant maximum and minimum boiling points. Refrigerants comprising this mixture do not combine chemically, yet the mixture provides constant characteristics.

Refrigerant in Group Al (R-ll). Chemical combination of carbon, chlorine, and fluorine.

Which of the following refrigerants is popular in the industrial refrigerating system; also popularly absorption system of refrigerant

Which of the following is a function of air conditioning?

Oxygen is approximately what percent by weight in the atmosphere?

Substances that have the ability to absorb moisture from the air are called:

When the dry bulb and the wet bulb temperatures are identical, the air is said to be

In what form that water exists in air?

When air is heated, what happened to its relative humidity?

The Horizontal Scale (Abscissa) in the Psychrometric Chart represents

Most people are comfortable with the relative humidity of

The temperature below which water vapor in the air will start to condense.

Which of the following is not used as method to measure air velocities?

It is a form of oxygen photochemically produced in nature.

What is the Chemical formula of Ozone?

In the upper atmosphere, ozone is made by ultraviolet light reacting with

The ozone concentration of 0.10 parts per million (ppm) is generally considered the maximum permissible for how many hours exposure?

How may moisture be removed from air?

In cooling cycle, the dry bulb temperature (db) of the air is lowered. When this happens the relative humidity

What is the effect of superheating the refrigerant?

In sensible heating the absolute humidity remains constant but the relative humidity

The relative humidity becomes 100 % and where the water vapor starts to condense.

Why should you avoid bending or twisting of fan blades in an air conditioning unit?

A type of refrigerant that will not damage the ozone layer.

Which of the following is the type of refrigerant that damages Ozone layer?

Large-bulb alcohol thermometer used to measure air speed or atmospheric conditions by means of cooling.

The phenomenon that warm air rise and cold air settle is called

Which of the following components of the window air conditioning system must be cleaned annually?

Air delivered to the room from the supply duct, moving at a velocity of 150 ft/min or more is called

Carries needed to deliver air to the conditioned space. It is made of sheet of metals like aluminum, galvanized sheet steel and some structural materials that will not burn.

From what principle that air ducts operate?

Which of the following is the common classification of ducts?

It is used deliver concentrated airstreams into a room. Many have one-way or two-way adjustable air stream deflectors.

It is used to control the air-throw distance, height, and spread, as well as the amount of air.

It is used to deliver widespread, fan-shaped flows of air into the room.

Which of the following fans in air conditioning systems which can be classified as centrifugal flow?

The most common controller in the heating and cooling systems.

A thermostat that functions as increase or decrease instead of starting and stopping system is called

A number used to compare energy usage for different areas. It is calculated by dividing the energy consumption by the fottage of the conditioned area.

The ratio of the rated cooling capacity divided by the amount of electrical power used

Heat exchanger in which water flows by gravity over the outside of the tubes or plates.

A popular air conditioning system that includes a single outdoor condenser, three independent evaporators, and individual evaporator temperature control. The condensing unit is located outside on a slab. They are frequently used in legal and medical offices, motels and homes without ducts.

An air conditioning system which is a combination of heating and cooling system. It is designed to serve an individual room or zone.

Which of the following is to be checked as regular monthly maintenance schedule of a console air conditioning units?

Which of the following is to be checked as part of the weekly maintenance schedule of a console air conditioners?

A mechanism that removes moisture.

When coil surface temperature is below the dew point of the air

Nitrogen occupied almost how much of the Earth’s Atmosphere.

An instrument used in measuring air velocity by velocity­-pressure method.

What is the specific humidity of dry air?

The useful energy transfer in Btu/hr divided by input power in Watts. This is just the coefficient of performance expressed in mixed units.

If EER is the energy efficiency ratio, and COP is the coefficient of performance then

The rate of energy removal from the low temperature area is known as

The refrigeration cycle with highest coefficient of performance for any given temperature limits of all the refrigeration cycles.

A Carnot power cycle running in reverse is

Which of the following is a reversed Rankine vapor cycle?

The most common type of refrigeration cycle, finding application in household refrigerators, air conditioners for cars and houses, chillers and so on.

Also known as Brayton cooling cycle.

Which of the following is a reversed Brayton cycle?

A refrigeration cycle often used in aircraft airconditioning and gas liquefaction applications where a refrigerant with such characteristics is needed.

Also known as heat activated refrigeration cycle.

Which of the following refrigeration cycle is practical when large quantities of waste or inexpensive heat energy are available.

Similar to the vapor compression cycle, with one major change there is no compressor and no external work is used to compress the refrigerant.

Which of the following cycle is bulky and involves toxic fluids, hence it is unsuitable for home and autocooling.

Compressors used for small, and medium size refrigerators,

Compressors used in the largest machines usually 200 tons or larger.

A product of computer-aided manufacturing and precision machining, were introduced commercially in the late 1980’s as replacements for reciprocating compressors in small residential air conditioners.

Condensers used in small and medium sized, up to approximately 100 tons refrigerators.

For efficient operation, the condensing temperature should not be lower than

For efficient operation, the condensing temperature should not be more than

Condensers used for larger capacities refrigerators.

The equipment that operates at the low pressure in the refrigerator.

Evaporators for cooling air are externally finned and are known as

Coolers and chillers for water generally operate with an average temperature difference of

To avoid freezing problems, entering refrigerant should be

A small suction line

Suction lines should not be sized too large, as a reasonable velocity is needed to carry oil from the evaporator back to the compressor. For horizontal suction lines, the recommended minimum velocity is

For vertical suction lines, the velocity should be

Type of turbine used for low heads, high rotational speeds and larger flow rates

Which of the following turbine consists of a rotating shaft on which buckets or blades are mounted.

A Pelton wheel is known as

Impulse turbine are generally employed where the available head is very high

Efficiency of impulse turbine is in the range of

To keep the deflected jet out of the way of the incoming jet, the actual angle is limited to approximately

Which of the following turbines are centrifugal pumps operating in reverse?

Also known as Francis turbines or radial flow turbines

Reaction turbines are when the total available head is small, typically below

The efficiency of reaction turbine is in the range of

In reaction turbine, water enters the turbine housing with a pressure

Also known as propeller turbine

In a typical hydroelectric generating plant using reaction turbines, the turbine is generally housed in a

After the water passes through the turbine, it is discharged through the draft tube to the receiving reservoir known as the

If a draft tube is not employed, water maybe returned to the tailwater by way of a channel known as the

The turbine, draft tube and all related parts comprise what is known as

When a forbay is not part of the generating plant’s design, it will be desirable to provide a _____ in order to relieve the effects of rapid changes in flowrate.

To keep the deflected jet out of the way of the incoming jet, the actual angle is limited to approximately

The spontaneous vaporization of the fluid, resulting in a degradation of pump performance.

The minimum fluid energy required at the pump inlet for satisfactory operation is known as

The actual fluid energy at the inlet

Throttling the input line to a pump and venting or evacuating the receiving tank