Worksheets › Class 12 › Ray Optics and Optical Instruments
Class 12 Ray Optics and Optical Instruments worksheet
CBSE Physics. Mirror and lens formulas, refraction, total internal reflection, prisms, microscopes and telescopes. Every sheet has 20 questions in three sections and an answer key, and the numbers change every time.
Sample questions
Real questions from this chapter, as the app sets them. Tap Answer to see the answer and working.
Section A · multiple choice
- 1.
An object is 12 cm in front of a concave mirror of focal length 25 cm. The image distance v is:
- −8.11 cm
- −23.1 cm
- −37 cm
- 23.1 cm
Answer
(d) 23.1 cm
1/v + 1/u = 1/f with u = −12 cm, f = −25 cm
- 2.
An object is 55 cm from a concave lens of focal length 40 cm. The image distance v is:
- 23.2 cm
- −147 cm
- −23.2 cm
- −95 cm
Answer
(c) −23.2 cm
1/v − 1/u = 1/f with u = −55 cm, f = −40 cm
- 3.
A coin lies at the bottom of a tank of liquid 12 cm deep, of refractive index 2. Seen from directly above, it appears to be at a depth of:
- 12 cm
- 7 cm
- 24 cm
- 6 cm
Answer
(d) 6 cm
apparent depth = real depth ÷ n
Section B · short answer
- 4.
An object 7 cm tall stands 28 cm in front of a concave mirror of focal length 40 cm. Find the position, size and nature of the image.
Answer
v = 93.3 cm (behind the mirror); height 23.3 cm; virtual and erect
1/v = 1/f − 1/u; m = −v/u = 10/3
- 5.
An object 7 cm tall is 42 cm from a concave lens of focal length 40 cm. Find the position, size and nature of the image.
Answer
v = −20.5 cm (on the same side as the object); height 3.41 cm; virtual and erect
1/v = 1/f + 1/u; m = v/u = 20/41
Section C · long answer
- 6.
Two convex lenses of focal lengths 15 cm and 10 cm are 60 cm apart on the same axis. An object is 60 cm in front of the first. Find where the final image forms.
Answer
the first image is at 20 cm; the final image is 13.3 cm from the second lens (real, beyond it)
the first image acts as the object for the second lens at u = −40 cm
Fresh sheets for your child
In the app, every Ray Optics and Optical Instruments sheet is new: the app remembers the questions your child has already had and leaves them out. Print the sheet as a PDF, or use notebook mode and write the answers in a notebook.
Coming soon for Android and iPhone.