MCQ ON LASER
Q1. The emission process responsible for producing laser is
a)Spontaneous emission b) stimulation emission c.) ultraviolet emission d.) infrared emission
Q2. For laser action to occur, the medium must have at least
a.) Four energy levels b.) two energy levels c.) three energy levels d.) none of above
Q3. Ordinary light does not have
a.) monochromaticity b.) coherence c.) high intensity d.) all of above
Q4. The life time of metastable state is
a.)10-5 sec b.) 10-3 sec c.)10-8 sec d.) 10-7 sec
Q5. The ratio of Einstein’s coefficients A and B is
a) 8πh v3/c3 b.) 2π h3v3/c3 c.) (2π hv/c)3 d.) 8 hc/π
Q6. In ruby laser which ions give rise to laser action?
a.) Al2O3 b.)Al3+ c.) Cr3+ d.) none of them
Q7. Which of the following laser have the highest efficiency?
a.)Ruby b.) semiconductor c.) He-Ne d.) carbon-dioxide
Q8. The wave length of emitted light in Ruby laser is
a.)632.8 nm b.) 694.3 nm c. 683.2 nm d 649.3 nm
Q9. In He – Ne laser the most favorable ratio of He to Ne for satisfactory laser action is
a.) 1: 10 b.) 10 : 11 c.) 10: 1 d.) 11:10
Q10. CO2 laser produces laser light in the range of wavelength
a.) 50μm – 24.8μm b.) 20μm – 10.6μm c.) 24.8μm – 20μm d.) 10.6μm – 9.4μm
Q11. The wavelength of light emitted from He-Ne laser is
a.) 6843 A0 b.) 6328 A0 c.) 6943 A0 d.) 6523 A0
Q12. Pulsed laser light is produced from
a ) ruby laser b.) carbon laser c.) CO2 laser d.) none of above
Q13.Usually, population inversion in gas laser is achieved by
a.) optical pumping b) electric discharge c.) thermal pumping d.) chemical pumping
Q14. Which of the following is not a characteristic of LASER?
a.) coherence b) .high divergence c.) highly directional d.) extreme brightness
Q15. The hologram contains the information about,
a.) amplitude of the object b.) phase of the object c) both (a) & (b) d.) none of the above
Q16. The information carrying capacity of the hologram is,
a.) less than ordinary photograph b.) more than ordinary photograph
c.) equal to ordinary photograph d.) none of the above
Q17. In normal state of energy the incident high energy photons will be
a.) stimulated b.) absorbed c.) cause X-ray emission d.) cause laser production
Q18. In He-Ne laser the lasing action is produced by
a.) He-Ne both b.) Ne only c.) Electrons of He d.) none of above
Q19. The velocity of laser light is,
a.) Less than ordinary b.) light more than ordinary light
c.) equal to ordinary light d.) Different for different colours
Q20. Some lasers are referred to as being “cw.” What does “cw” mean?
a.) Circular wave b.) constant white c.) continuous wave d. clear white
Q21. In CO2 laser the discharge tube contains a mixture of CO2, N2 and He in the ratio of
a.) 15% : 70% : 15% b.) 70% : 15% : 15% c.) 15% : 15% : 70% d.) 25% : 25%:50%
Q22. What was the active medium used in the first working laser ever constructed?
- A diamond block b.) He-Ne gas c.) ruby rod d.) CO2 gas
Q23. In Ruby LASER , the host crystal is
a.) Al2O3 b.) MnO2 c.) CaCO3 d.) none of above
Q24. In spontaneous emission process the photon is
a.Lost b.) created c. (a) & (b) both d. none of the above
Q25. In stimulated emission process the number of coherent photons are;
a.) 3 b.)1 c) 2 d. none of the above
READ ALSO:
Ruby Laser Construction and Working
Semiconductor LASER Construction and Working
Six Major Misconceptions in LASER what Student Thinks
How to Find LASER Wavelength Using a Diffraction Grating in the Lab
He-Ne gas Laser: Its Principle, Construction and Working
Carbon dioxide (CO2) gas Laser
Answer Keys LASER MCQ:
These are answers of MASER MCQ.
1Correct : b
2Correct : c
3Correct : d
4Correct : b
5Correct : a
6Correct : c
7Correct : b
8Correct : b
9Correct : c
10Correct : d
11Correct : b
12Correct : a
13Correct : b
14Correct : b
15Correct : c
16Correct : b
17Correct : b
18Correct : b
19Correct : c
20Correct : c
21Correct : c
22Correct : c
23Correct : a
24Correct : c
25Correct : c
