Optics

Gap-fill exercise

  
Fill in all the gaps, then press "Check" to check your answers. Use the "Hint" button to get a free letter if an answer is giving you trouble. You can also click on the "[?]" button to get a clue. Note that you will lose points if you ask for hints or clues!
1. Focal length of a convex mirror is 50 cm. Its radius of curvature is cm.
2. Radius of a concave mirror is 25 cm. Its focal length is cm.
3. A concave mirror produces a 10 cm long image of an object 2 cm long. The magnification produced is ± .
4. An object 1 cm high is held near a concave mirror of magnification 10. The image will be ± cm tall.
5. A concave mirror produces a real image 10 mm tall of an object 2.5 mm tall placed at 5 cm from the mirror. The magnitude of focal length of the mirror is cm.
6. A mirror gives an erect and enlarged image of an object held between pole and principal focus of the mirror.
7. The power of lens is 2.5 D. Its focal length is cm.
8. When a ray of light travels from air into water obliquely, it bends the normal.
9. One is the power of a lens of focal length 1 metre.
10. A mirror is used to get the larger view.