Engineering Physics Unit 3 Notes AKTU (BAS101)

Unit 3: Wave Optics – AKTU syllabus topics

• Interference of Light: Thin Film Interference, Wedge Shaped Film Interference, Newton Rings and Applications
• Diffraction of Light: Fraunhofer Single Slit Diffraction, Fraunhofer Double Slit Diffraction, Absent Spectra
• Diffraction Grating: Grating Spectra Dispersive Power, Resolving Power of Grating
• Rayleigh Criterion Resolution

Most asked AKTU PYQ questions from Unit 3

1. Q6b. What is a diffraction grating? Discuss the phenomenon of diffraction due to plane diffraction grating. (10 marks, 2020-21)
2. Q1h. State the Rayleigh criteria of resolution. (2 marks, 2021-22)
3. Q1h. State Rayleigh criterion of Resolution. Also define resolving power. (2 marks, 2020-21)
4. Q6a. What do you mean by a wedge-shaped film? Discuss the interference due to it and obtain the expression for the fringe width. (10 marks, 2021-22)
5. Q6b. Discuss the formation of Newton's rings. Show that the diameters of the bright rings are proportional to the square root of odd natural numbers. (10 marks, 2021-22)
6. Q2d. Calculate the thickness of a soap bubble thin film that will result in constructive interference in reflected light. The film is illuminated with light of wavelength 5000 Å and the refractive index of the film is 1.45. (10 marks, 2020-21)
7. Q6a. Describe the formation of Newton's rings in monochromatic light. Show that in reflected light, the diameters of dark rings are proportional to the square roots of natural numbers. (10 marks, 2020-21)
8. Q2c. Explain interference in thin films due to reflected light of uniform thickness and obtain the condition of bright and dark rings. (7 marks, 2024-25)
9. Q5b. A parallel beam of sodium light of wavelength 5880 Å is incident on a thin glass plate of refractive index 1.5 such that the angle of refraction in plate is 60°. Calculate the smallest thickness of the plate, which will make it appear dark by reflection. (7 marks, 2024-25)
10. Q5b. Give the construction and theory of plane transmission grating and explain the formation of spectra by it. (7 marks, 2023-24)

Other Engineering Physics units

• Unit 1 Notes
• Unit 2 Notes
• Unit 4 Notes
• Unit 5 Notes

Engineering Physics previous year papers

• PYQ 2024-25
• PYQ (Combined Papers)

More Engineering Physics resources

• Handwritten Notes: Unit 1 Handwritten Notes
• Handwritten Notes: Unit 4 Handwritten Notes
• Handwritten Notes: Unit 5 Handwritten Notes
• Important Questions: Important Questions (All Units)

Engineering Physics exam preparation

• Engineering Physics Unit 3 Important Questions
• Engineering Physics Unit 3 PYQ
• Engineering Physics Important Topics
• Engineering Physics Predicted Paper