Home / Practice / Class 11 / Physics / Physical optics
Physical optics
Written by Dr. Hamza Farooq (Physics)
8 Class 11 Physics questions with answers and explanations.
Printable worksheet with answer key
All questions with answers
-
Interference of light provides evidence that light behaves as a:
- 1 Wave
- 2 Particle
- 3 Neutral object
- 4 Sound
Show answer
Correct answer: Wave
Interference is a wave property.
Report a mistake
-
In Young's double slit experiment, the fringe spacing is proportional to:
- 1 Wavelength
- 2 Intensity
- 3 1 / wavelength
- 4 Slit width only
Show answer
Correct answer: Wavelength
Fringe spacing = wavelength x distance to screen / slit separation.
Report a mistake
-
Polarisation shows that light waves are:
- 1 Transverse
- 2 Sound like
- 3 Longitudinal
- 4 Neutral
Show answer
Correct answer: Transverse
Only transverse waves can be polarised.
Report a mistake
-
A diffraction grating has 5000 lines per cm. The grating spacing is:
- 1 5 x 10⁻³ m
- 2 2 x 10⁻⁶ m
- 3 5 x 10⁻⁶ m
- 4 2 x 10⁻⁴ m
Show answer
Correct answer: 2 x 10⁻⁶ m
d = 1 / 5000 cm = 2 x 10⁻⁴ cm = 2 x 10⁻⁶ m.
Report a mistake
-
Newton's rings are produced by:
- 1 Polarisation
- 2 Dispersion
- 3 Reflection only
- 4 Thin film interference
Show answer
Correct answer: Thin film interference
They form from interference in the thin air film between a lens and a plate.
Report a mistake
-
The wavelength of visible light is of the order of:
- 1 1 m
- 2 10⁻⁷ m
- 3 10⁻² m
- 4 10³ m
Show answer
Correct answer: 10⁻⁷ m
It is about 400 to 700 nm.
Report a mistake
-
A diffraction pattern is clearest when the slit width is:
- 1 Infinite
- 2 Comparable to the wavelength
- 3 Zero
- 4 Much larger than the wavelength
Show answer
Correct answer: Comparable to the wavelength
Diffraction is strongest for narrow gaps.
Report a mistake
-
Light is polarised when its vibrations are:
- 1 Zero
- 2 Circular only
- 3 Random
- 4 Restricted to one plane
Show answer
Correct answer: Restricted to one plane
Polaroid filters allow one plane.
Report a mistake