USCG Exam Practice · Light List, ranges, and light characteristics
Which light characteristic is defined as having equal periods of light and darkness?
- AOcculting (Oc)
- BFlashing (Fl)
- CIsophase (Iso)✓ correct
- DFixed and Flashing (FFl)
Why C is correct
Isophase (Iso) is specifically defined as a light with equal periods of light and darkness. Occulting has longer light than dark; Flashing has shorter light than dark; Fixed and Flashing is a continuous light with a superimposed brighter flash.
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