21. Diffraction is special type of

- Reflection
- Refraction
- Interference
- Polarization

22. Extended source is needed in

- Youngs double slit experiment
- Bi prism Experiment
- Newtons Ring Experiment
- None of them

23. Find the maximum value of resolving power of a grating 3 cm wide having 5000 lines per cm, if the wavelength of light used is 5890 A^{o}.

- 40000
- 45000
- 4500
- 5000

24. For all transparent material substances, the index of refraction

- is less than 1
- is greater than 1
- is equal to 1
- Could be any of the given answers; it all depends on optical density

25. Fraunhofer diffraction at a Plane Grating. What is the meaning of grating element for a diffraction grating?A It is the width of a single slit

- It is the width of the opaque space
- It is the distance between two slits
- It is the width of diffraction grating

26. Fraunhofer diffraction is observed when

- Only screen is placed at finite distance
- source is placed at finite distance
- neither source nor screen is at finite distance
- None of these

27. Fresnels type diffraction is observed when

- Only screen is placed at finite distance
- Only source is placed at finite distance
- Both source and screen are at finite distance
- Neither source nor screen is at finite distance

28. Fringe spacing is defined as the distance between two Consecutive

- Crests
- Bright fringes only
- Dark fringes only
- Bright or dark fringes

29. How the intensity of secondary maxima varies in case of Fraunhofer diffraction pattern for single slit?

- Intensity of secondary maxima decreases on either sides
- Intensity of secondary maxima remains constant on either side
- Intensity increases and decreases alternately
- Intensity of secondary maxima increases on either sides

30. If we narrow the distance between two slits in Youngs experiment the fringes width

- Increases
- Decreases
- Remains same
- becomes zero

MCQ Multiple Choice Questions and Answers on Interference and Diffraction

Interference and Diffraction Trivia Questions and Answers PDF

Interference and Diffraction Question and Answer

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