A convex lens is used as a magnifying glass to read small print…
Contributed by StemPy LabTry it on paper first. A hint, the key idea and the worked solution are here when you need them.
A convex lens is used as a magnifying glass to read small print.
- Where must the page be, compared with the focus?
- Describe the image, and say why it cannot be caught on a screen.
- You slowly lift the lens away from the page, past its focal length. What happens to the print you see?
Need a reminder? The key ideaShow
Convex lens, object beyond : a smaller real inverted image between and , as in a camera. Object at : the same size, at . Object between and : a larger real image beyond , as in a projector. Object inside : a larger virtual upright image on the object's side, as in a magnifying glass. A concave lens always gives a smaller, virtual, upright image.
The worked solution
Have you tried it?
Work it out on paper first. It is fine to get stuck or make a mistake: that is how we learn. When you are ready, go through the solution one step at a time, and check each step against your own.
Step 1. (a) The page must be closer to the lens than .
Step 2. (b) The image is on the page's side: virtual, upright and larger. The rays spread out after the lens and never meet, so no screen can catch it.
Step 3. (c) Near the print grows huge and blurs. Past the image becomes real and inverted: the print turns upside down.
Answer: (a) inside . (b) virtual, upright, larger; the light never meets. (c) it blurs, then flips upside down.
Discussion (0)
Log in to join the discussion.
Loading…