The oil in a vacuum pump should be changed _____

A) about every five minutes of pump operation
B) only when changing from one refrigerant to another
C) immediately after pumping down a wet or contaminated system
D) about every 25 hours of pump operation


Answer: C

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If using spring brakes when hauling a heavy load a complete stop will

a. Be impossible. b. Take a long time. c. Take a short amount of time.

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A frictionless 400-mm-diameter piston sits on top of 2 kg of water in a cylinder such that the pressure is initially at 120 kPa at a temperature of 80ºC. Heat is added until the piston rises a distance of 2 m, at which state the quality of the steam is nearest:

A) 0.19 B) 0.14 C) 0.088 D) 0.034

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____________________ is the force that resists motion between the surfaces of two objects or forms of matter.

Fill in the blank(s) with the appropriate word(s).

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In the figure above, if there was an open at terminal "C", what would the voltage signal to the PCM be?

A. 0 volts B. About 1½ volts C. About 3½ volts D. 5 volts

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