1st Year Physics Chapter 09 Physical Optics Mcqs With Answers

1st Year Physics Chapter 09 Physical Optics Mcqs With Answers, In Chapter 9 behavior of optics has been discussed. Wavefront is an important factor in optics. It is discussed by the Huygens principle. Optics also shows Interference. It is further explained by Young’s Double Slit Experiment. Newton also worked on these principles. Light shows diffraction on optics. Diffraction is also shown by Narrow Slit, Diffraction Grating and by crystals. The phenomenon of polarization is also seen in optics.

 

1st Year Physics Chapter 09 Key Points

 

1st Year Physics Chapter 09 Physical Optics Mcqs With Answers

 

Question#1. Optically active crystals rotate the?

• Vibrating plane
• Polarization plane
• Diffraction plane
• Interference plane

Question#2. Which is not an optically active substance?

• Sugar
• Tartaric acid
• Water
  
• Sodium chlorate

Question#3. In double slit experiment, we observe?

• Interference fringes only
• Diffraction fringes only
• Both interference and diffraction fringes
• Polarized fringes

Question#4. When light incident normally on thin film, the path difference depends upon?

• Thickness of the film only
• Nature of the film only
• The angle of incidence only
• All thickness, nature, and angle of incidence

Question#5. Which one of the following properties of light does not change with the nature of the medium?

• Velocity
• Wavelength
• Amplitude
• Frequency

Question#6. Huygen wave theory explain?

• Diffraction
• Interference
• Polarization
• Photoelectric effect

Question#7. The photoelectric effect was explained by?

• Hertz
• Fresnel
• Einstein
• Plank

 

Question#8. According to Einstein, light travels from one place to another in the form of?

• Waves
• Particles
• Photons
  
• It was not his discovery

Question#9. Longitudinal waves do not exhibit?

• Reflection
• Refraction
• Diffraction
• Polarization

Question#10. Signal from the T.V remote control travels:

• With speed of sound
• With the speed of light
• With the speed of ultrasonic
• With the speed of supersonic

Question#11. A point source of light placed in a homogenous medium gives rise to?

• A cylindrical wavefront
• An elliptical wavefront
• Spherical wavefront
• A plane wavefront

Question#12. The locus of all points in a medium having the same phase of vibration is called?

• Crest
• Trough
• Wavelength
• Wavefront

Question#13. Which one of the following is nearly monochromatic light?

• Light from a fluorescent tube
• Light from a mercury lamp
• Light from a sodium lamp
• Light from a simple lamp

Question#14. Two sources of light are coherent if they emit rays of?

• Same wavelength
• The same amplitude of vibration
• Same wavelength with a constant phase difference
• Same amplitude and wavelength

Question#15. When the crest of one wave falls over the trough of the other wave, this phenomenon is known as?

• Polarization
• Constructive interference
• Destructive interference
• Diffraction

Question#16. In Young’s double slit experiment, the fringe spacing is equal to (d=slit separation and D = distance of the screen from slits):

• dλD
• 2λd/D
• λD/d
• λd/D

Question#17. In the Young double-slit experiment, if white light is used?

• Alternate dark and bright fringes will be seen
• Coloured fringes will be seen
• No interference fringes will be seen
• Impossible to predict

Question#18. The velocity of light was determined accurately by?

• Newton
• Michelson
• Huygen
• Young

Question#19. The condition of constructive interference of two coherent beams is that the path difference should be?

• Integral multiple of λ/2
• Integral multiple of λ
• Odd integral multiple of λ/2
• Even integral multiple of λ

Question#20. In an interference pattern:

• Bright fringes are wider than dark fringes
• Dark fringes are wider than bright fringe
• Both dark and bright fringes are equal width
• Central fringes are dimmer than the outer fringes

Question#21. In Young’s double-slit experiment, the separation between the slit is halved and the distance between the slit and screen is doubled. The fringe width is:

• Remain the same
• Double
• Half
• Quadrupled

Question#22. The blue color of the sky is due to?

• Diffraction
• Reflection
• Polarization
• Scattering

Question#23. A light ray traveling from denser to rarer medium suffers a phase change of?

• 0°
• 90°
• 180°
• 45°

Question#24. When one mirror of a Michelson Interferometer is moved a distance of 0.5 mm, we observe 2000 fringes. What will be a wavelength of light used?

• 5000nm
• 5000A°
  
• 500m
• 2000μm

Question#25. Diffraction effect is:

• More for round edge
• Less for round edge
• More for a sharp edge
• Less for a sharp edge

Question#26. The wavelength of X – rays is of the order of?

• 10A°
• 1000A°
• 1A°
• 100A°

Question#27. The wavelength of X-rays falling at a glancing angle of 30° on a crystal with atomic spacing 2 x 10^-10m for the first-order diffraction is?

• 4×10^-10m
• 2×10^-10m
• 0.02×10^-10m
• 20×10^-10m

Question#28. A diffraction grating has 500 lines per mm. Its slit spacing or grating element will be equal to?

• 500mm
• 5×10^-3mm
• 2×10^-5mm
• 2×10^-3mm

Question#29. In a plane-polarized light electric vibration are:

• In all direction
• In two mutually perpendicular directions
• Taking place perpendicular to the direction of propagation of light
• No vibration at all

Question#30. Light on passing through a Polaroid is?

• Plane polarized
• Un-polarized
• Circularly polarized
• Elliptically polarized

Question#31. Which one of the following cannot be polarized?

• Radio waves
• Ultraviolet rays
• X-rays
• Ultrasonic waves

Question#32. A compact disc having rulings of 0.5 μm each wide shows colors under white light due to?

• Equally spaced
• Distance between them increases
• Distance between them does not remain constant
• They are adjacent with no space in between

Question#33. In monochromatic red light, a blue book will probably appear to be?

• Black
  
• Purple
• Green
• No scientific reasoning available

Question#34. A polarizer is used to?

• Reduce the intensity of light
• Produce polarized light
• Increase intensity of light
• Both a and b

Question#35. In a double-slit experiment, if one of the two-slit is covered then?

• No interference fringes are observed
• No diffraction fringes are observed
• No fringes observed
• Interference pattern not disturbed

Question#36. ________ gives the definition of a metre in terms of the wavelength of red cadmium light.

• Newton
• Einstein
• Michelson
• Galileo

Question#37. In Michelson interferometer to switch the fringe from bright to dark the mirror should be displaced through?

• λ/(b)
• λ/3
• λ/6
• λ/4

Question#38. In the shadow of a ball the central portion appears bright that happens due to?

• Interference
• Diffraction
• Polarization
• Refraction

Question#39. Which experiment shows that wavelength of light is smaller than that of sound?

• Diffraction
• Polarization
• Interference
• Reflection

Question#40. Crystals of material can behave as?

• Convex lens
• Interferometer
• Diffraction grating
• Concave