How does a remote bulb thermostat work?

How does a remote bulb thermostat work?
 
  A) The metal in the bulb expands and contracts with temperature changes.
  B) The remote bulb communicates with the thermostat using wireless communication.
  C) Pressure in the bulb rises and falls with temperature.
  D) An electronic sensor in the bulb sends signals back to the thermostat.

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[Ques. 2] Potential relays measure the back ________ developed across the ________ winding to operate the relay.
 
  A) amp draw, run B) emf, run C) emf, start D) amp draw, start

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[Ques. 3] The American Wire Gauge rates wires in size from smallest to largest as:
 
  A) 4 mm to 40 mm. B) 000 to 50. C) 50 to 0000. D) 40 mm to 4 mm.

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[Ques. 4] Mica and disc capacitors are used on:
 
  A) Motor circuits. B) Power transmission lines.
  C) Electronic circuit boards. D) Heavy-duty power supplies.

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[Ques. 5] What gauge wire is most often used for residential receptacle circuits?
 
  A) 16 gauge B) 18 gauge C) 14 gauge D) 12 gauge