Which of the following is the reason when the crankcase is cooler than the suction line?

Which of the following will cause an automatically controlled F-12 compressor to start?

The temperature bulb of a solenoid valve is attached to the ______

Which of the following would not cause high suction pressure?

The most likely cause of high superheat would be

The suction pressure in a Freon system should be

With one machine serving several compartments, with one compartment reaches the desired temperature in that compartment is maintained by:

Which of the following would not be cause for a refrigerating system to short cycle on HP cutout?

Which one is commonly used liquid absorbent?

An instrument for determination of the composition of the gas mixture by measuring variations in the thermal conductivity.

What is the cycle where a refrigeration system generally operates?

The function of the expansion valve is to:

An engineer inspected an air-conditioning unit. He found out that the unit does not produce any cooling effect, however, the air-conditioning unit is running. He checked the temperatures of the condenser and evaporator and had the unit run. He found out that there was no change in temperature. What should he do?

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

The temperature at which water vapor in the atmosphere begins to condense is known as the:

Dirt and foreign materials normally build-up on the side of the condenser tubes. To ensure adequate condenser capacity, a certain factor is used in calculating the overall heat transfer through the walls of the tubes including the heat transfer rate of the layers dirt and foreign materials. What is this factor?

The solenoid valve controls the

Low suction pressure is caused by

What is the effect if the refrigerant is removed from the system too fast?

If one of the ship’s service boxes suddenly stops cooling, the most likely cause would be the malfunction of the:

What do you call the device that is used as a lowpressure control and high-pressure cutout on a compressor?

Which of the following plant is suitable for peak load?

What is the combination of a wet and dry bulb thermometer is called a

If the solenoid valve closed by accident, the compressor would be stopped by which of the following?

The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy diagram represents:

Which of the following is the probable cause of hot suction line?

Which of the following devices will prevent the relief valve from opening in the event of excessive pressure?

What is the first step that must be done when securing a system?

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

What is the effect of superrheating the refrigerant?

What do you call a material in a dryer?

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

When adding oil to a Freon system, one must be sure that

Which of the following type valves are not found on a Freon -12 system?

there were a 15°F to 20°F temperature differential between the temperature corresponding to the pressure at the compressor discharge and the temperature at the condenser outlet, it would probably indicate the need for

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

What is the use of back pressure regulating valve?

For Brayton cycle, the result of regeneration is:

The temperature of the refrigerant is highest just before it enters the:

Which of the following types of valve are not used for suction or discharge?

What do you call the liquid reaching the compressor through the suction?

When hot soup was served in a cup during dinner, an engineer was so eager to drink it. Since it was hot, he added ice cubes of ice to cool the soup stirred it. He noticed that dew starts to form on the outermost surface of the cup. He wanted to check the temperature of the outermost surface of the cup. What is the temperature equal to?

When ordering an expansion valve which of the following information is necessary?

The solenoid valve is controlled by

An instrument used in measuring air velocity by velocity pressure method

If the compressor short-cycles on the highpressure cutout, which of the following would you check?

Which of the following statements is correct? The relative humidity of an air water vapor mixture

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.

The heat used to change a liquid to a gas or vapor is called latent heat of

If the head pressure is too high:

Whal is the cause of Iiquid “slugging"?

The purpose of the low-pressure cutout switch is to:

There are three basic boiler types, namely:

Which of the following would cause the suction switch to remain open?

Where is solenoid coil installed?

The psychrometric chart in air conditioning determines the

If there is too much lube oil in the system, what must be done?

Which of the following is not essential to a centrifugal type of compressor system?

Dry ice is

The dividing point between the high pressure and low pressure sides of the refrigeration cycle occurs at the:

An automatically controlled Freon -12 compressor will start when the

Chimneys that rely on natural draft are sometimes referred to as

Which of the following is the most common method of heat flow in refrigeration?

Oil is added to a Freon compressor by

Whatis the instrument used to register relative humidity?

The solenoid valve controls which of the following

The suction pressure control valve is actuated by which of the following?

A thermostat is a

It prevents the refrigerant from the condenser to go back to the compressor.

What do you usually do to correct slugging and flooding back?

If the compressor discharge becomes frosted, the irobable cause would be

A mechanism that removes moisture.

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

Bell-Coleman Cycle is also known as ________

Which of the following characteristics that is not desirable in a refrigerant?

The solenoid valve is actuated by which of the following?

The process that takes place in the evaporator is called:

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

Which of the following would cause a high head pressure?

If any of the electrically controlled devices in a Freon system malfunction, which of the following valve will also automatically shut off?

The cooling component of a refrigeration cycle is called ______

Which of the following is not essential to a comiression refrigeration system?

Which of the following uses a secondary refrigerant?

Fans that are used to draw combustion products through the furnace bed, stack, and pollution control system by injecting air into the stack after combustion.

What will happen if the expansion valve is opened too wide?

What do you call a plate or vane used to direct or control movement of fluid or air within the confined area?

A good refrigerant should have a

A leaky discharge valve can usually be detected by

What is the use of back pressure regulating valve?

Moisture in a system will cause a:

How is a thermostatic valve tested?

When charging Freon system, all the valves should be in their normal position except the:

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:

If refrigeration controls were constructed with little or no differential, the:

What usually happens if the specific gravity of the brine is too low?

Refrigerant leakage from the compressor crankcase is prevented by

A valve that releases steam from the boiler by opening at a 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

What will happen when the pressure at any point inside ¢ centrifugal pump goes below the vapor pressure corresponding to the temperature of the liquid?

When heavy electrical currents are involved, the thermostat will be operated by a:

What is the use of the suction pressure regulating valve?