Question 2·Multiple choice
What does a watch's 'power reserve' tell you?
- A.How long the battery lasts before replacement
- B.How deep it can safely go underwater
- C.How long it runs on a full wind before stoppingCorrect answer
- D.How many seconds a day it gains or loses
The story behind it
Power reserve is the time a fully wound mainspring can keep the watch going before it needs winding again. A dial gauge that shows how much is left is itself counted as a complication, since it does more than tell the time.