Illumination Engineering Interview Questions:

Following are the below Illumination Engineering Interview Questions and Important Questions which is very useful for interviews and exams

1. Explain the basic nature of light.

2. Define and explain the following terms : (i) Mean horizontal candle power (ii) Mean spherical candle power (iii) Mean hemi-spherical candle power (iv) Flux (v) Solid angle (vi) Specific consumption (vii) Glare (viii) Absorption factor (ix) Beam factor and (x) Waste light factor.

3. Explain laws of illumination.

4. Derive relation between E, I and L for a uniform diffuse source.

5. Derive expressions for the illumination on a surface (i) when it is normal and (ii) when it is inclined to the axis of a beam of incident light.

6. Define : (i) plane angle and solid angle, (ii) Depreciation factor, (iii) Cosine inverse law, (iv) Polar curve.

7. What are polar curves ? Mention the uses of polar curves.

8. What are polar curves ? Explain Rousseau diagram and its importance in illumination engineering ?

9. Explain Rousseau diagram and its importance in illumination engineering.

10. Why is tungsten selected as the filament material and on what factors does its life depend ?

11. Prove that in a filament lamp the diameter of filament is directly proportional to I^2/3, where I is the current flowing in the filament.

12. Explain the advantages of using inert gas in filament lamps and the purpose to get the filament as coiled coil.

13. Describe the construction and working of a filament lamp. Compare it with fluorescent lamp.

14. Discuss the effects of voltage variation on the life and illumination as regards tungsten filament lamp and fluorescent lamp.

15. Explain the working of halogen lamp.

16. Describe with a neat sketch the principle of electric discharge lamp. State the advantages and disadvantages of discharge lamps over the filament lamp and give their applications.

17. Explain with a neat diagram the principle of operation of a sodium vapour lamp. Mention its use.

18. Describe the construction and principle of operation and application of mercury vapour lamp.

19. Explain the operation of the following with circuit diagrams: (a) LP sodium vapour lamp, (b) HP mercury vapour lamp.

20. Write construction and working of Neon lamp.

21. Explain the working of a fluoescent tube with the help of the circuit giving the function of various parts. How stro­boscopic effect is eliminated in fluorescent tube lighting.

22. Describe the working of fluorescent tube. What are the functions of starter and choke.

23. Explain street lighting. Mention its principles and explain in detail.

24. With the help of circuit diagrams explain the working of the following light sources : (a) High pressure mercury vapour lamp (b) Fluorescent tube (c) Carbon-arc lamp.

25. What are the usual values of power factors for the above lamps ? Indicate the systems of illumination where above lamps are used.

26. Describe the construction and principle of operation and application of fluorescent lamp.

27. Discuss the construction and principle of operation and application of (a) filament lamp (b) sodium vapour lamp, (c) mercury vapour lamp (d) fluorescent lamp.

28. Compare metal filament lamp with discharge lamp.

29. Compare the merits of alternative lighting schemes using incandescent lamps, sodium vapour lamps or fluorescent lamps for industrial lighting.

30. Why CFL lamps are becoming more popular, nowadays ? Discuss technically.

31. What do you understand by direct, indirect, and semi-indi­rect lighting ?

32. State and describe various types of lighting schemes.

33. Describe in brief the requirements of good lighting. Enu­merate the factors to be considered while designing an indoor lighting scheme.

34. How does designing of indoor and outdoor system differ ? Explain method for designing an indoor system.

What arc the requirements of good street lighting ?

35. What are the general principles that are usually employed in the design of street lighting explain.

36. Explain the specular reflection principle of street lighting.

37. Enumerate the various factors to be considered while de­signing street lighting.

38. What are the aims of street lighting and how are they achieved ? List types of lamps used for street lighting.

39. Explain the various factors to be taken into account for designing schemes for (i) street lighting (ii) floodlighting.

40. Explain the factors to be taken into account for designing schemes for (i) street lights, (ii) floodlighting and (iii) high­way lighting.

41. Write short notes on the following:

• Laws of illumination.
• Polar curves.
• Rousseau’s diagram.
• Sodium vapour lamp.
• Mercury vapour lamp.
• Halogen lamp.
• Fluorescent lamps.
• CFL
• Street lighting.
• Essential requirement of good lighting.
• Floodlighting.