A device that does not switch on and off motors directly is a:
A) Heavy-duty relay. B) Contactor. C) Light-duty relay. D) Motor starter.
[Ques. 2] An air conditioner with a thermostatic expansion valve is operating with a condenser saturation temperature of 95F and a liquid-line temperature of 92F. The factory-specified subcooling for the current operating condition is 10F. The technician should:
A) Move some of the charge from the low side of the system to the high side of the system to balance the charge.
B) Leave the charge alone because it is cooling even better than factory specifications.
C) Add charge because the system is undercharged.
D) Recover charge because the system is overcharged.
[Ques. 3] Wattmeters read true power in a circuit. This can be expressed by what equation?
A) Power = amps volts B) Power = ohms divided by volts
C) Power = ohms volts power factor D) Power = amps voltage power factor
[Ques. 4] What type of measurements require a true RMS meter to obtain accurate results?
A) Strip heater current B) Shaded-pole motor current
C) Nonlinear, electronic switching loads D) Linear alternating current loads
[Ques. 5] What is a transient voltage?
A) A voltage that is traveling from one part of the circuit to another part of the circuit
B) A momentary surge or spike of voltage that can be several times the normal circuit voltage
C) A voltage that affects only the moving, or transient portions of the circuit
D) A voltage that temporarily transforms to current or resistance