Engineering Physics Unit 4 – Fiber Optics and Laser: AKTU previous year questions
48 AKTU questions from Unit 4 (Fiber Optics and Laser) asked in 2021–2026, tagged by marks, year and topic. In short: about 26 marks of every paper come from this unit; the most asked topic is Optical Fiber Basics (18 times); 46 questions came back in a later year. The latest ones are listed below; on the page you can filter them by 2-mark or long questions, topic and repeats.
Unit 4 previous year questions
- Differentiate between spontaneous emission and stimulated emission of radiation. (2 marks, 2026, Laser Fundamentals)
- Explain the role of population inversion in laser action. (2 marks, 2026, Laser Fundamentals)
- What is the difference between step index fibre and graded index fibre? Explain with suitable diagrams. Also discuss the mechanism of light propagation in both types of optical fibres. (7 marks, 2026, Optical Fiber Basics)
- Describe the construction and working principle of a He-Ne laser with the help of a suitable diagram. (7 marks, 2026, Types of Lasers)
- What are the sources of attenuation of signal in an optical fibre? Explain. (7 marks, 2026, Fiber Optic Communication)
- What do you mean by population inversion? (2 marks, 2025, Laser Fundamentals)
- Differentiate Spontaneous Emission and Stimulated Emission. (2 marks, 2025, Laser Fundamentals)
- State the formula to calculate the cut off parameter and Number of modes in the fiber. (2 marks, 2025, Optical Fiber Basics)
- A Fiber made of silicon with a diameter of the core is such that it consists of core and claddings refractive indexes of 1.40 and 1.37. Find the numerical aperture of Fiber. (2 marks, 2025, Optical Fiber Basics)
- Discuss construction and working of He-Ne Laser. (7 marks, 2025, Types of Lasers)
- Explain the process of absorption of radiation, spontaneous emission and stimulated emission with diagram. Show that A21/B21 = 8πhv³/c³ (7 marks, 2025, Laser Fundamentals)
- Explain the construction and working principle of an optical fiber. Define acceptance angle and numerical aperture, and derive the relation between them. (7 marks, 2025, Optical Fiber Basics)
Most asked Unit 4 topics
- Optical Fiber Basics – asked 18 times
- Laser Fundamentals – asked 14 times
- Types of Lasers – asked 9 times
Unit 4 question pattern
- 2-mark questions: 19 asked in 2021–2026
- 7-mark questions: 20 asked in 2021–2026
- 10-mark questions: 9 asked in 2021–2026
- About 26 marks from Unit 4 in every paper
- 46 questions were asked again in a later year
Unit 4 questions year by year
- 2026: 5 Unit 4 questions asked (25 marks across that year's papers)
- 2025: 10 Unit 4 questions asked (50 marks across that year's papers)
- 2024: 9 Unit 4 questions asked (43 marks across that year's papers)
- 2023: 9 Unit 4 questions asked (48 marks across that year's papers)
- 2022: 10 Unit 4 questions asked (68 marks across that year's papers)
- 2021: 5 Unit 4 questions asked (34 marks across that year's papers)