Monday, 12 August 2013

A test from chapter 9 and 10 i.e Physics Optics and Optical Instruments of Physics part 1. This is Free online test for FSc and Entry test Preparation for UET, NUST, FAST, GIKI, PIEAS, NFC, Punjab University, UHS, other Engineering Universities and Medical Colleges.

  1. Basic principle of an optical fiber is:
    1. Reflection
    2. Polarization
    3. Scattering
    4. Total internal reflection
  2. Large aperture of telescope is used for
    1. Greater magnification
    2. Reducing lens aberration
    3. Greater resolution
    4. Ease of manufacture
  3. Blue colour of sky is due to
    1.  Scattering of light
    2. Interference of light
    3. Dispersion
    4. Sunemits more of blue light
  4. In the Young’s double slit experiment, if monochromatic light used is replaced by white light, then
    1. No fringes are observed
    2. All bright fringes become white
    3. All bright fringes have colours between violet and red
    4. Total destructive interfare will take place
  5. Huygen’s proposed 1st time that light from a luminous source travelin space as wave in
    1. 1978
    2. 1778
    3. 1878
    4. 1678
  6. A surface on which all the points have the same state of vibration is known as
    1. Wave-length
    2. Wave-let
    3. Wave-packet
    4. Wave-front
  7. A line normal to the wave-front, showing the direction of propagation of light is called
    1. Wave-guide
    2. Beam of light
    3. Wave-vector
    4. Ray of light
  8. Sound waves cannot be:
    1. Refracted
    2. Polarized
    3. Reflected
    4. Made to produce interference
  9. To study of interference and diffraction effects of light we need light in the form of:
    1. Spherical wave-fronts
    2. Wave-fronts from the point source
    3. Segments of large spherical wave-fronts
    4. All of these
  10. Huygen’s principles enable us to determine the _______of new wave-front
    1. Position
    2. Both position and shape
    3. Shape
    4. None of these
  11. The interference of light is only observed when the following condition(s) is/are fulfilled
    1. Mono chromatic light
    2. Coherent source
    3. Sources which are closely placed
    4. All of these
  12. If m is an integer;  condition of destructive interference is:
    1. Path diff.= 3 (lamda)
    2. Path diff.= 3(lamda)/2
    3. Path diff.= m(lamda)
    4. Path diff=(m+1)(lamda)/2
  13. Fringe width is inversely proportional to the
    1. Separation between the two slits
    2. Order of the fringe\
    3. Wavelength of light use
    4. Distance between slits and screen
  14. The distance between the two neighboring dark fringes is equal to
    1. L(lamda)/d
    2. M(lamda)
    3. (m+1/2)(lamda)
    4. 2m+1(lamda/2)
  15. A convex lens is dipped in a liquid whose refractive index is equal to the material of the lens. Then its focal length will become:
    1. Infinite
    2. Extremely small
    3. Zero
    4. Extremely large
  16. In refraction phenomenon, which quantity remains unchanged
    1. Wavelength
    2. Frequency
    3. Velocity
    4. All of these
  17. A bulb is placed between two plane mirrors inclined at an angle of 60(degree). The number of images formed is
    1. 3
    2. 5
    3. 4
    4. 6
  18. The focal length of a convex lens is 3.5cm.The magnification power for an eye whose least distance of vision is 35 cm is:
    1. 10
    2. 12
    3. 11
    4. 13
  19. Yellow sodium light of wavelength 589 nm emitted by a single source passes through two narrow slits 1.00 m apart. The interference pattern is observed on a screen 100 cm away. The distance between the two adjacent bright fringes is
    1. 589 um
    2. 589 pm
    3. 589 nm
    4. none
  20. When one leg of a Michelson interferometer is lengthened slightly, 150 dark fringes sweep through the field of view. If the light used has  lamda= 480 nm. How far was the mirror in that leg moved:
    1. 40 m
    2. 0.036 mm
    3. 50 m
    4. none
  21. A tourmaline crystal is being used as an analyzer. In one complete rotation of the crystal the number of excitation will be:
    1. 2
    2. 1
    3. 4
  22. If the cover of a red book is observed in monochromatic blue light. It will appear:
    1. White
    2. Black
    3. Red
    4. blue
  23. Two lenses of power+12 and -2 diopters are placed in contact, the power of combination is:
    1. 10 diopters
    2. 6 diopters
    3. 8 diopters
    4. 12 diopters
  24. Refractive index of malarial depends upon:
    1. Nature of malarial
    2. Temperature
    3. Wave length of light
    4. All of these
  25. An arrangement which detects plane polarized light is known as:
    1. Polarizer
    2. Analyser
    3. Transmission
    4. none
  26. The central ring is bright in case of newton’s rings produced by:
    1. Reflection edges
    2. Transmission
    3. none
  27. With monochromatic light the fringe width in a double slit experiment is 1.33 mm. If the whole apparatus is immersed in water of refractive index 1.33 the new fringe width will be:
    1. 1.33 m
    2. 1.33x1.33 mm
    3. 1mm
    4. (1.33/2)m
  28. To get three images of a single ovject, one should have the plane mirrors at an angle of
    1. 90
    2. 160
    3. 120
    4. 30
  29. The sources are said to be coherent if they have:
    1. Constant phase difference
    2. White light
    3. Very far apart
    4. They are driven by two source
  30. Distance of distinct vision is 25 cm. The focal length of the convex lens is 5 cm. it can act as a magnifier of magnifying power:
    1. 5
    2. 16
    3. 6
    4. 2
  31. The far point for normal eye is:
    1. 25 cm
    2. 50 m
    3. 25 m
    4. infinity
  32. To increase the resolving power of telescope we should use;
    1. Wider objective
    2. Shorter objective
    3. Wider eyepiece
    4. Shorter eyepiece
  33. Which of the following descries that light is a transverse wave?
    1. Polarization
    2. Interference
    3. Scattering
    4. all
  34. X-ray diffraction is very useful in determining the structure of
    1. Crystals
    2. DNA
    3. Hemoglobin
    4. all
  35. The fringe width for red colour as compared to that for violet colour is approximately
    1. Four times
    2. Three time
    3. Two times
    4. Eight times
  36. The branch of physics which deals with the nature and propagation of light is known as
    1. Geometrical optics
    2. Quantum optics
    3. Physical optics
    4. all
  37. In a young douled slit experiment the frequency of the coherent sources of light is f and the distance between screen and sources is 1m. the distance between the sources is d. if the screen is moved 5m toward sources the fringe width becomes:
    1. Halved
    2. Quadrupled
    3. Doubles
    4. None
  38. In optical fiver, the source of light is:
    1. Laser
    2. Bulb
    3. LED
    4. Both a and b
  39. The path difference in thin film depends upon
    1. Angle of incidence
    2. Nature of the film
    3. Thickness of the film
    4. all
  40. The diameter of the objective of a telescope is D, the light use has wavelength lamda. The resolving power of the telescope is
    1. L(lamda)/D
    2. 1.22 D/(lamda)
  41. Diamond shines due to
    1. Reflection
    2. Total internal reflection
    3. Refraction
    4. all
  42. An object is placed 20 cm from a convex lens having a focal length of 10 cm. how far is the image from the object?
    1. 10 cm
    2. 30 cm
    3. 20 cm
    4. 40 cm
  43. The use of light as transmission carrier wave in fiber optics has advantages over radio waves carriers:
    1. Much wider band-width
    2. Immunity from electromagnetic interference
    3. Transmission is possible to inaccessible places
    4. all
  44. A simple telescope in normal adjustment has an objective of focal length 100 cm and eye piece of focal length 5 cm. where is the final image formed
    1. 20 cm
    2. Focus
    3. Infinity
    4. Within the focus of eye-piece of focal length 5 cm. where is the final image formed
  45. In an astronomical telescope the objective of long focal-length forms_________image
    1. Real, inverted, magnified
    2. Real, inverted, diminished
    3. Real, erect, magnified
    4. None



  1. D                  2. C         3A           4A           5D           6D           7D           8B           9C           10B         11D        `12B       13A        14A              15A        16B         17B         18C         19A        20B         21B         22C         23A        24A        25B         26C         27C                28A        29A        30C         31D        32A        33A        34D        35C         35D        37A        38D        39D        40D                41A        42B         43D        44C         45B

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