Which of the following describes a retroreflective scan?
a. The scanning method in which the light beam transmitted from the transmitter is reflected back to the
receiver by the target to be detected
b. The scanning method in which the target to be detected passes between the transmitter and receiver,
interrupting the light beam
c. The scanning method in which the receiver responds only to depolarized light reflected from a corner
cube reflector or polarized sensitive tape
d. The scanning method in which a target is detected as it passes between a photoelectric sensor and a
reflector
[Ques. 2] NEC Article 430, Part VII covers _____.
a. motor circuits involving special equipment and hazardous locations
b. motor and controller circuit overload protection
c. motor controllers
d. the criteria for selecting the type of enclosure to use for controllers in classified locations
[Ques. 3]
[Ques. 4] 
In the figure above, symbol E represents a _____.
a. float switch
b. temperature switch
c. pressure switch
d. foot switch
[Ques. 5] In the figure above, symbol F represents a _____.
a. float switch
b. temperature switch
c. pressure switch
d. foot switch
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