CLD Electrical Systems & Lighting Control

Question 1

What is the primary function of a 0–10 V dimming signal?

Accepted Answer

Low‑voltage DC dimming control

Answer

Phase‑cut line dimming

Answer

DMX control

Answer

On–off switching

Question 2

Typical North‑American branch circuit voltage for lighting is:

Accepted Answer

120 V

Answer

208 V

Answer

277 V

Answer

347 V

Question 3

Relay panels in lighting control systems serve to:

Accepted Answer

Switch branch circuits

Answer

Dim drivers

Answer

Measure power quality

Answer

Boost voltage

Question 4

DMX‑512 protocol is mainly used for:

Accepted Answer

Stage lighting control

Answer

Office troffers

Answer

0‑10 V loops

Answer

PoE power

Question 5

Phase‑cut dimmers reduce lamp brightness by:

Accepted Answer

Chopping AC waveform

Answer

Changing frequency

Answer

Reducing CRI

Answer

Increasing current

Question 6

DALI enables luminaires to:

Accepted Answer

Communicate digitally with addresses

Answer

Share one analog loop

Answer

Provide PoE power

Answer

Flash emergency beacons

Question 7

Emergency egress luminaires must be powered by:

Accepted Answer

A dedicated emergency source

Answer

Any normal circuit

Answer

Photocell circuit

Answer

USB supply

Question 8

PoE lighting delivers:

Accepted Answer

Low‑voltage DC and data via Cat‑5/6

Answer

120 V AC

Answer

DMX only

Answer

Fiber‑optic light

Question 9

Mechanically‑held contactors are preferred because they:

Accepted Answer

Save energy after switching

Answer

Need constant coil current

Answer

Cannot be automated

Answer

Are for dimming