Keep It Cool! Refrigerator Quiz
by Staff
Most people take their refrigerators for granted, except when they break down. While the main idea of how refrigerators work is fairly simple, how they are built is more complex. Chill out with this cool quiz to test your knowledge of how refrigerators work.

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