To focus parallel light rays to the smallest possible
Chapter 35, Problem 35.28(choose chapter or problem)
To focus parallel light rays to the smallest possible spot, should you use a lens with a small f@number or a large f@number? Explain
Unfortunately, we don't have that question answered yet. But you can get it answered in just 5 hours by Logging in or Becoming a subscriber.
Becoming a subscriber
Or look for another answer