CBSE Questions for Class 12 Medical Physics Ray Optics And Optical Instruments Quiz 8 - MCQExams.com

The refractive indices of glass and quartz w.r.t. air are 3/2 and 12/5 respectively. The refractive index of quartz w.r.t. glass is:
  • 8/5
  • 5/8
  • 5/18
  • 18/5
Which surfaces are known as refracting surfaces in the glass prism?
  • Rectangular surfaces
  • Triangular surfaces
  • Circular surfaces
  • Cylindrical surfaces
Which of the following signifies Snell's law?
  • $$ \dfrac {sin \ i}{ sin\ r}= constant $$
  • $$ \dfrac {sin \ r}{ sin\ i}= constant $$
  • $$ sin \ i + sin \ r = Constant$$
  • none of the above 
Tyndall effect is shown by:
  • particles in colloidal solution. 
  • particles in a very fine suspension
  • large particles like stones.
  • both A and B
Which of the following phenomenon is involved in Tyndall effect?
  • Reflection of light.
  • Refraction of light.
  • Scattering of light.
  • Magnification of light.
What is refraction?
  • Phenomenon in which ray of light deviates from its path at the surface of separation of two media.
  • Phenomenon in which ray of light reflects from its path at the surface of separation of two media.
  • Phenomenon in which ray of light deviates from its path at the surface of 1st media
  • None
A persons image appears on the far side of an optical instrument, upside down. What is the optical instrument? 
492638_646cdf52c3c7494b9b50b4321994cbbb.png
  • Concave mirror
  • Convex mirror
  • Plane mirror
  • Concave lens
  • Convex lens
A ray of light incident on the interface of the medium $$A$$ and $$B$$ and it passes through medium $$B$$ as shown in above figure. Choose the correct option.
487095_48e351d8c4be4711ad02f2ce81dfd79a.png
  • Medium 1 is more dense than medium 2
  • Medium 1 less dense than medium 2
  • The speed of the light in medium 1 is greater than the speed of the light in medium 2
  • The frequency of the light in medium 1 is greater than the frequency of the light in medium 2
  • The wavelength is the same in medium 1 and medium 2
A given ray of light suffers minimum deviation in an equilateral prism P. Additional prisms Q and R of identical shape and material are now added to P, as shown in the figure. The ray will suffer:
477130.PNG
  • same deviation
  • greater deviation
  • total internal reflection
  • no deviation
Refraction of light occurs when:
  • light passes through a narrow opening.
  • light passes into a new transparent material (not head on) in which it travels at a new speed.
  • light strikes the edge of an object.
  • light becomes polarized.
  • light passes through a diffraction grating.
The object and the image are at distance of $$9\  cm$$ and $$16\  cm$$ respectively from the focal length of an equiconvex lens of radius of curvature $$12 \ cm$$. The refractive index of the material of the lens is:
  • 1$$.45$$
  • $$1.5$$
  • $$1.55$$
  • $$1.6$$
Which of the following observations cannot be explained by Tyndall Effect?
  • Sunlight entering a smoke filled dark room from a tiny hole.
  • Sunlight entering from a canopy of dense forest.
  • Speed of light in vacuum is $$3 \times 10^8\ m/s$$
  • Light passed through a milk solution.
For the myopic eye, the far point is farther away than the normal.
  • True
  • False
For the myopic eye, the far point is farther away than normal.
  • True
  • False
If the image of distant objects is formed in front of the retina, the defect of vision may be
  • myopia
  • hypermetropia
  • cataract
  • astigmatism
State whether true or false :
Pupil controls the amount of light entering an eye.
  • True
  • False
The inability among the elderly to see nearby objects clearly because of the weaking of the ciliary muscles is called
  • far-sightedness
  • near-sightedness
  • presbyopia
  • astigmatism
A magnifying glass is what kind of lens, and where do where should I place the lens relative to the object to see an image larger than the object and right-side-up? (f stands for the focal length of the lens.)
  • Type of Lens - convex, Location of Lens Relative to Object In terms of f - closer than f to object
  • Type of Lens - concave, Location of Lens Relative to Object In terms of f - closer than f to object
  • Type of Lens - convex, Location of Lens Relative to Object In terms of f - between f and $$2f$$ from object
  • Type of Lens - concave, Location of Lens Relative to Object In terms of f - between f and $$2f$$ from object
  • Type of Lens - convex, Location of Lens Relative to Object In terms of f - greater than $$2f$$ from object
If the power of an eye lens increases, then the defect of vision so produced is known as
  • Colour blindness
  • Long sightedness
  • Short sightedness
  • None of the above
A planet is observed by an astronomical reflecting telescope having an objective of focal length 16 m and an eye - piece of focal length 2 cm.
  • the distance between the objective and the eye - piece is 16.02 m.
  • the angular magnification of the planet is 800.
  • the image of planet is erect.
  • the objective is larger than eye - piece.
The type of lens used as a simple microscope.
  • Binocular lens
  • Plano concave lens
  • Concave convex lens
  • Convex lens
A luminous object is separated from a screen by distance $$d$$. A convex lens is placed between the object and the screen such that it forms a distinct image on the screen. The maximum possible focal length of this convex lens is
  • $$4d$$
  • $$2d$$
  • $$d/2$$
  • $$d/4$$
Telescopes make the far objects appear:
  • Farther
  • Nearer
  • Highly magnified
  • Disappear
Find the refractive index of the glass which is a symmetrical convergent lens if its focal length is equal to the radius of curvature of its surface
  • 2
  • 1.5
  • 1
  • $$\dfrac{4}{3}$$
The least distance of distinct vision is ________.
  • 25 m
  • 340 cm
  • 25 cm
  • 17 cm
The defect hypermetropia can be corrected by using a ..................
  • Convex lens
  • Concave lens
  • Concave mirror
  • Convex mirror
The anguThe angular resolution of 10cm diameter telescope at a wavelength of $$5000nm$$ is of order of the
  • $$ 10^{4}$$ rad
  • $$ 10^{-4}$$ rad
  • $$ 10^{-6}$$ rad
  • $$ 10^{6}$$ rad
The hypermetropia is a
  • short sighted defect
  • long sighted defect
  • bad vision due to old age
  • none of these
The optical length of an astronomical telescope with magnifying power of 10, for normal vision is 44cm. What is focal length of the objective?
  • 40cm
  • 22cm
  • 10cm
  • 4cm
Which is true for the far sightedness or hypermetorpia from the following?
  • Eye lens does not become thin as per requirement
  • Distant object cannot be seen clearly
  • Nearby object cannot be seen clearly
  • Defect can be corrected by using concave lens
Which coloured light scatters least by fog and smoke?
  • Green
  • Yellow
  • Blue
  • Red
At which place in the eye, image is formed of a person is far-sightedness (hypermetropia)?
  • On retina
  • Behind the retina
  • Infront of retina
  • On lens of eye
Which colour of light is scattered the most (maximum) in the atmosphere?
  • Red
  • Yellow
  • Blue
  • Green
The lens used to correct long sightedness or hypermetropla.
  • Convex lens
  • Concave lens
  • Simple lens
  • Cylindrical lens
What is the least distance of distinct vision of a normal human eye?
  • 10 cm
  • 100 cm
  • 25 cm
  • 25 m
The apparent flattening of the sun at sunset and sunrise is due to 
  • refraction
  • diffraction
  • total internal reflection
  • interference
  • polarization
A light beam of diameter $$\sqrt{5}R$$ is incident symmetrically on a glass hemisphere of radius II and of refractive index $$n=\sqrt{3}$$. The radius of the beam at the base of hemisphere is:
639790_ca9777182d5441a0b650d142cffcf335.PNG
  • $$\frac{R}{\sqrt{3}}$$
  • $$\frac{R}{2\sqrt{3}}$$
  • $$\frac{\sqrt{3}}{2} R$$
  • $$\frac{R}{2}$$
A quarter cylinder of radius $$R$$ and refractive index $$1.5$$ is placed on a table. A point object $$P$$ is kept at a distance of $$mR$$ from it as shown in figure. For what value of $$m$$ for which a ray from $$P$$ will emerge parallel to the table?
639328_7962f12d8e714bb991d09ee09782c239.png
  • $$\dfrac { 2 }{ 3 } $$
  • $$\dfrac { 3 }{ 2 } $$
  • $$\dfrac { 4 }{ 3 } $$
  • $$\dfrac { 3 }{ 4 } $$
A double convex lens of glass of refraction index $$\mu$$ is immersed in a medium of refractive index $$\mu_{1}$$. If a parallel beam emerges undeviated through the lens, then:
  • $$\mu = \mu_{1}$$
  • $$\mu = \dfrac {1}{\mu_{1}}$$
  • $$\mu > \mu_{1}$$
  • $$\mu < \mu_{1}$$
For the myopic eye, the defect is cured by
  • Convex lens
  • Concave lens
  • Cylindrical lens
  • Toric lens
A small laboratory telescope has an objective lens of focal, length $$140 cm$$ and an eye-piece of focal length $$6 cm$$. Then, separation between the objective and eye-piece is :
  • $$140 cm$$
  • $$24 cm$$
  • $$156 cm$$
  • $$146 cm $$
The resolving power of telescope depends on
  • Focal length of eye lens
  • Focal length of objective lens
  • Length of the telescope
  • Diameter of the objective lens
A ray of white light of incident on a spherical water drop whose center is C as shown in figure. When observed from the opposite side, the emergent light.

630683_c4f77cf5b7c24ec7b6e66f3ece546c06.JPG
  • Will be white and will emerge without deviating
  • Will be internally reflected
  • Will split into different colors such that the angles of deviation will be different for different colors
  • Will split into different colors such that the angles of deviation will be the same for all colors
A person can see objects clearly only upto a maximum distance of $$60\ cm$$. His eye defect, nature of the corrective lens and its focal length are respectively.
  • Myopia, convex, $$60\ cm$$
  • Myopia, concave, $$60\ cm$$
  • Hypermetropia, concave, $$60\ cm$$
  • Contract, convex, $$60\ cm$$
A point object is placed on the axis of the concave mirror at a distance of $$60cm$$ from the focal point of the mirror. Its image is formed at the point of the object, then the focal length of the mirror is
  • $$15cm$$
  • $$30cm$$
  • $$60cm$$
  • $$120cm$$
There is a small black dot at the centre C of a solid glass sphere of refractive index $$\mu$$. When seen from outside, the dot will appear to be located:
  • Away from C for all values of $$\mu$$
  • At C for all values of $$\mu$$
  • At C for $$\mu =1.5$$, but away from C for $$\mu\neq 1.5$$
  • At C only for $$\sqrt{2} \leq \mu \leq 1.5$$
A water drop in air reflects the light rays as
A microscope is focussed on an ink mark on the top of a table. If we place a glass slab of $$3$$cm thick on it, how should the microscope be moved to focus the ink spot again? The refractive index of glass is $$1.5$$.
  • $$2$$cm upwards
  • $$2$$cm downwards
  • $$1$$cm upwards
  • $$1$$cm downwards
A ray of light passing through a semicircle block from air is shown below. Consider the given figure and select the correct option which correctly identifies the true (T) and false (F)?
(i) There is no change in the direction of ray at $$P$$ because light ray incident on semicircular block at $$90^{\circ}$$.
(ii) As light rays enters the semicircular block, its frequency remains the same.
(iii) Wavelength of light rays as it enters the block decreases.
(iv) Speed of light as it enters the block increases.
759295_ff9d7caae18749c68509ceb7b5dc67d9.png
  • T F F T
  • F T T F
  • T T T F
  • F F F T
The construction of Worlds largest telescope is started in which country?
  • America
  • Denmark
  • Japan
  • Chile
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