I. Multiple Choice Questions. (1/2 mark each)
Write the letter of the correct answer in the brackets provided against each question.
1) The wave theory of light was proposed by [ ]
A) Newton B) Maxwell C) Huygens D) Faraday.
2) Shallow water region behaves as… [ ]
A) Boundary of the media B) Denser medium C) Rarer medium D) None of the above
3) Bending of light waves around an obstacle is known as [ ]
A) Refraction B) Diffraction C) Polarisation C) Reflection
4) Newton proposed this theory of light [ ]
A) Corpuscular theory B) Wave theory C) Electromagnetic theory D) All the above
5) When a crest of one wave falls on the trough of another wave then the interference is [ ]
A) Normal B) Abnormal C) Constructive D) Destructive
6) Lasers are used in the treatment of diseases of [ ]
A) Brain B) Bone fracture C) Heart D) Lung
7) Solid angle is measured in [ ]
A) Lumen B) Candela C) Phot D) Steradian
8) Speed of light in vacuum is [ ]
A) 5x108m/s B) 3x105m/s C) 3x108m/s D) 3×10-8m/s
9) Lumen is the unit of [ ]
A) Luminous flux B) Solid Angle C) Luminous intensity D) Diffraction
10) The process of achieving population inversion is called [ ]
A) Projecting B) Stimulated emission C) Processing D) Pumping
II. Fill in the blanks with suitable answers. (1/2 mark each)
11) Wave theory was proposed by —–
12) For constructive super position of waves, phase difference between the waves should be equal to —–
13) A wave under goes a phase change of — on reflection
14) Newton proposed — theory of light
15) Corpuscles are —– by the reflecting surface
16) Corpuscles are —– by the refracting surface
17) The size of corpuscles are —– for different colours
18) According to corpuscular theory, the velocity of light in —– medium is greater than that in —– medium
19) Corpuscular theory could not explain the phenomenon of —– , —– and —–
20) Huygens originally thought that for the propagation of light waves —– is required.
21) Candela is the unit of —–
22) The process of achieving ‘Population inversion’ is called —–
23) The wave length of ruby laser is —–
24) Expanded form of LASER is —–
25) The unit of solid angle is —–
26) —– is an example for gaseous laser
27) —– makes a laser light optical music
28) A —– light source gives coloured fringes
29) in computers, lasers are used to retrieve stored information from a —–
30) —– are used for bloodless surgery
III. Match the following (1/2 mark each) Group A Group B
31) Corpuscular theory [ ] A) Bending of a wave
32) Wave theory [ ] B) Maxwell
33) Electromagnetic theory [ ] C) Demonstration of waves
34) Diffraction [ ] D) Huygens
35) Ripple tank [ ] E) Newton
Group A Group B
36) Solid laser [ ] A) Rate of rotation of earth
37) He- Ne laser [ ] B) Pumping
38) Astronomy [ ] C) Three dimensional photography
39) Holography [ ] D) Stellar objects
40) Population inversion [ ] E) Ruby laser
ANSWERS
I. 1) C 2) C 3) B 4) A 5) D 6) A 7) D 8) C 9) A 10) D
II. 11) Christian Huygens 12) Zero (or) an integral multiple of 2Π 13) Π or 180o 14) corpuscular 15) repelled 16) attracted 17) different 18) Denser, rarer 19) interference, diffraction, polarisation 20) a medium 21) Luminous intensity 22) Pumping 23) 6943 Ao 24) Light Amplification by stimulated Emission of Radiation 25) steradians 26) He-Ne 27) coherence 28) White 29) compact Disc (CD) 30) Lasers
III. 31) E 32) D 33) B 34) A 35) C 36) E 37) A 38) D 39) C 40) B