12th Class Physics Ray Optics Question Bank

done MCQs - Ray Optics and Optical Instruments Total Questions - 23

• question_answer1)

  The direction of ray of light incident on a concave mirror is shown by PQ while directions in which the ray would travel after reflection is shown by four rays marked 1, 2, 3 and 4 (Figure). Which of the four rays correctly shows the direction of reflected ray?

  A)
  1 done clear
  B)
  2 done clear
  C)
  3 done clear
  D)
  4 done clear
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• question_answer2)
  A car is moving with at a constant speed of \[60\text{ }km\] \[{{\operatorname{h}}^{-1}}\] on a straight road. Looking at the rear-view mirror, the driver finds that the car following him is at a distance of 100 m and is approaching with a speed of \[5\,\,km\,\,{{\operatorname{h}}^{-1}}\]. In order to keep track of the car in the rear, the driver begins to glance alternatively at the rear and side mirror of his car after every \[2\,\,s\] till the other car overtakes. If the following statement(s) is/are correct?
  A)
  The speed of the car in the rear is \[65\,\,km\,/\,h\]. done clear
  B)
  In the side mirror the car in the rear would appear to approach with a speed of \[5\,\,km\,\,{{\operatorname{h}}^{-1}}\] to the driver of the leading car. done clear
  C)
  In the rear view mirror the speed of the approaching car would appear to decrease as the distance between the cars decreases. done clear
  D)
  In the side mirror, the speed of the approaching car would appear to increase as the distance between the cars decreases. done clear
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• question_answer3)
  When an object is placed between f and 2f of a concave mirror, the image formed is   
  A)
  Real, diminished done clear
  B)
  Real, magnified done clear
  C)
  Virtual, diminished done clear
  D)
  Virtual, magnified done clear
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• question_answer4)
  ________ mirror has real focus.
  A)
  Concave done clear
  B)
  Convex done clear
  C)
  Plane done clear
  D)
  all of the above done clear
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• question_answer5)
  In two positions concave mirror produces magnified image of given object. The positions are
  A)
  (i) At C, (ii) at F done clear
  B)
  (i) Between F and C, (ii) Between P and P done clear
  C)
  (i) Beyond C, (ii) Between P and F done clear
  D)
  (i) At C, (ii) between P and F done clear
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• question_answer6)
  Convex mirrors are preferred over plane mirrors as rear view mirror in automobile since
  A)
  The image formed is magnified. done clear
  B)
  The image formed is real. done clear
  C)
  The field of view is large. done clear
  D)
  It is light weight. done clear
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• question_answer7)
  The focal length of a concave mirror is f. An object is placed at a distance x from the focus. The magnification is
  A)
  \[f\,+\,x)\,/\,f\] done clear
  B)
  \[f\,/\,x\] done clear
  C)
  \[x\,/\,f\] done clear
  D)
  \[f\,/\,(f\,+\,x)\] done clear
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• question_answer8)
  In a concave mirror, an object is placed at a distance \[{{x}_{1}}\] from the focus. Image if formed at a distance \[{{x}_{2}}\] from the focus. The focal length of the mirror is
  A)
  \[{{x}_{1}}{{x}_{2}}\] done clear
  B)
  \[{{x}_{1}}{{x}_{2}}\] done clear
  C)
  \[{{x}_{1}}/{{x}_{2}}\] done clear
  D)
  None of these done clear
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• question_answer9)
  The phenomena involved in the reflection of radio waves by ionosphere are similar to
  A)
  Reflection of light by a plane mirror. done clear
  B)
  Total internal reflection of light in air during a mirage. done clear
  C)
  Dispersion of light by water molecules during the formation of a rainbow. done clear
  D)
  Scattering of light by the particles of air. done clear
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• question_answer10)

  The optical density of turpentine is higher than that of water while its mass density is lower. Figure shows a layer of turpentine floating over water in a container. For which one of the four rays incident on turpentine in Figure, the path, shown is correct?

  A)
  1 done clear
  B)
  2 done clear
  C)
  3 done clear
  D)
  4 done clear
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• question_answer11)
  A short pulse of white light is incident from air to a glass slab at normal incidence. After travelling through the slab, the first color to emerge is
  A)
  blue done clear
  B)
  green done clear
  C)
  violet done clear
  D)
  red done clear
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• question_answer12)
  There are certain materials developed in laboratories which have a negative refractive index (Figure). A ray incident from air (medium 1) into such a medium (medium 2) shall follow a path given by:
  A)
  done clear
  B)
  done clear
  C)
  done clear
  D)
  done clear
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• question_answer13)
  The radius of curvature of the curved surface of a plano - convex lens is 20 cm. If the refractive index of the material of the lens be 1.5, it will
  A)
  act as a convex lens only for the objects that lie on its curved side. done clear
  B)
  act as a concave lens for the objects that lie on its curved side. done clear
  C)
  act as a convex lens irrespective of the side on which the object lies. done clear
  D)
  act as a concave lens irrespective of side on which the object lies. done clear
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• question_answer14)
  Radius of curvature of human eye is \[0.78\,\,cm\]. For an object at infinity, image is formed at \[3\,\,cm\] behind the refracting surface. The refractive index of eye is
  A)
  1.35 done clear
  B)
  3 done clear
  C)
  6.2 done clear
  D)
  1 done clear
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• question_answer15)
  The relationship between angle of incidence i, prism of angle A and angle of minimum deviation for a triangular prism is
  A)
  \[\operatorname{A}+{{\delta }_{\operatorname{m}}}=i\] done clear
  B)
  \[\operatorname{A}+{{\delta }_{\operatorname{m}}}=2i\] done clear
  C)
  \[\operatorname{A}+{{\delta }_{\operatorname{m}}}/2=i\] done clear
  D)
  \[2\operatorname{A}+{{\delta }_{\operatorname{m}}}=i\] done clear
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• question_answer16)
  Which of the following graphs is the correct angle of incidence vs. angle of deviation graph?
  A)
  done clear
  B)
  done clear
  C)
  done clear
  D)
  done clear
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• question_answer17)
  Magnifying power of a microscope depends on
  A)
  Color of light. done clear
  B)
  Focal length of objective and color of light. done clear
  C)
  Focal length of eyepiece and color of light. done clear
  D)
  Focal length of eyepiece and objective. done clear
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• question_answer18)
  Magnifying power of a telescope is
  A)
  \[1/{{f}_{0}}{{f}_{e}}\] done clear
  B)
  \[{{f}_{0}}/{{f}_{e}}\] done clear
  C)
  \[{{f}_{e}}/{{f}_{0}}\] done clear
  D)
  \[{{f}_{0}}{{f}_{e}}\] done clear
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• question_answer19)
  If \[{{m}_{1}}\] and \[{{m}_{2}}\] be the linear magnifications of the objective and eyepiece of a compound microscope, then the magnifying power of the compound microscope is
  A)
  \[{{m}_{1}}+{{m}_{2}}\] done clear
  B)
  \[{{m}_{1}}-{{m}_{2}}\] done clear
  C)
  \[{{m}_{1}}\times {{m}_{2}}\] done clear
  D)
  \[({{m}_{1}}+{{m}_{2}})/2\] done clear
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• question_answer20)
  In a compound microscope, image produced by objective is ______ and the image produced by eyepiece is _______.
  A)
  Real, real done clear
  B)
  Virtual, virtual done clear
  C)
  Real, virtual done clear
  D)
  Virtual, real done clear
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• question_answer21)
  Reflecting telescope utilizes
  A)
  Convex mirror done clear
  B)
  Concave mirror done clear
  C)
  Plane mirror done clear
  D)
  Prism done clear
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• question_answer22)
  The magnifying power of a telescope is M. If the focal length of the eyepiece is halved, the magnifying power will become
  A)
  \[M\,/\,2\] done clear
  B)
  \[4M\] done clear
  C)
  \[M\,/\,4\] done clear
  D)
  None of the above done clear
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• question_answer23)

  You are given the following 3 lenses. Two construct an astronomical telescope which one will you used as eyepiece and which one as objective?

  Lens Aperture (cm) Power (D) L1 8 3 L2 1 10 L3 1 6

  A)
  L1, L2 done clear
  B)
  L2, L1 done clear
  C)
  L2, L3 done clear
  D)
  L3, L1 done clear
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