Keep It Cool! Refrigerator Quiz
by Staff

What is the core principle that makes refrigerators work?

  • Evaporating liquids absorb heat.
  • Raising pressure lowers temperature.
  • Turning liquids to solids decreases temperature.

How long will it take the bacteria in your milk to spoil it if you leave it unrefrigerated?

  • two to three hours
  • eight to ten hours
  • one day

What is special about the liquid inside your refrigerator's coils?

  • It evaporates at a low temperature.
  • It is inert and light.
  • It is almost impossible to freeze it into a solid.

Why does your refrigerator need a compressor?

  • It compresses the refrigerant to begin the cooling cycle.
  • It cools the refrigerant so it will absorb heat from inside the refrigerator.
  • It turns the refrigerant into a liquid.

What does your refrigerator's expansion valve do?

  • separates low and high pressure zones
  • raises the refrigerant's temperature
  • pressurizes the refrigerant

At what temperature does water start to boil?

  • 100 degrees Fahrenheit
  • 212 degrees Fahrenheit
  • 407 degrees Fahrenheit

What happens to water's boiling point as you go higher in the mountains?

  • It goes down.
  • It goes up.
  • It stays the same.

Why does liquid nitrogen feel cold to humans even while it is boiling?

  • It has a very low boiling temperature.
  • It causes a chemical reaction in the skin.
  • It makes sweat evaporate from the skin.

What is a refrigerator's regenerating cycle?

  • the process through which the refrigerant is repeatedly heated and cooled
  • the process in which the temperature inside the refrigerator is reduced
  • the process of the compressor turning on every 15 minutes or so

After the refrigerant leaves your refrigerator's compressor, where does it go next?

  • to the outer coils
  • to the expansion valve
  • to the inner coils

What creates the low-pressure area in a refrigerator's inner coils?

  • the compressor sucking gas out of them
  • a lower temperature inside than outside the refrigerator
  • the expansion valve

At what temperature does ammonia boil?

  • -320 degrees Fahrenheit
  • -27 degrees Fahrenheit
  • 32 degrees Fahrenheit

Why don't refrigerators use pure ammonia as a refrigerant?

  • high toxicity
  • too costly
  • high boiling point

When were CFCs developed?

  • They were developed in the 1930s.
  • They were developed in the 1960s.
  • They always existed and were discovered, not developed.

Why did people stop using CFCs as refrigerants in new refrigerators?

  • They are bad for the ozone layer.
  • They were discovered to actually be toxic, after all.
  • There was a shortage of one of the chemicals that is used to make them.

What substances are used in the closed refrigeration system of a gas refrigerator?

  • ammonia, hydrogen and water
  • ammonia, oxygen and nitrogen
  • hydrogen, oxygen and carbon dioxide

What does the separator in a gas refrigerator do?

  • separates ammonia from water
  • separates water into hydrogen and oxygen
  • separates liquid ammonia from gaseous ammonia

What is the Peltier effect?

  • an electronic cooling process
  • the process of cooling via evaporation
  • a description of how something feels warm or cold in relation to something else

How do instant cold packs work?

  • by mixing water with ammonium-nitrate fertilizer
  • by mixing alcohol with hydrogen peroxide
  • by mixing liquid nitrogen with ammonia

How long do instant cold packs stay cold, and at what temperature?

  • 10 to 15 minutes at 35 degrees Fahrenheit
  • 25 to 30 minutes at 30 degrees Fahrenheit
  • up to 45 minutes at 40 degrees Fahrenheit