USCG Exam Practice · Light List, ranges, and light characteristics
Which light characteristic has equal periods of light and darkness?
- AOcculting (Oc)
- BFlashing (Fl)
- CIsophase (Iso)✓ correct
- DFixed and Flashing (FFl)
Why C is correct
Isophase (Iso) is defined as a light with equal periods of light and darkness. Occulting has more light than darkness; flashing has more darkness than light. Light List — light-characteristic (Iso).
Drill more Light List, ranges, and light characteristics questions
Every CaptainsGround answer cites the rule it tests — verified, not guessed. Try a free 5-question drill, no sign-up.
More practice questions
- A light charted as 'Fl R 4s' displays which characteristic?
- Which light characteristic is defined as having equal periods of light and darkness?
- Which statement correctly distinguishes an Occulting (Oc) light from a Flashing (Fl) li…
- A mariner observes a light that shows three flashes in a group, then a period of darkne…
- A Fixed and Flashing (FFl) light is best described as which of the following?
- When a light is listed in the Light List with no colour designation in its characterist…