Q.1 When a ray of light enters a glass slab, then

[AIIMS 2000]

(1) its frequency and velocity changes

(2) only frequency changes

(3) its frequency and wavelength changes

(4) its frequency does not change

Q.2 Match the elements of table I and table II.

Table I

1. Myopia

2. Hypermetropia

3. Presbyopia

4. Astigmatism

(1) 1-iii, 2-iv, 3-i, 4-ii

(3) 1-i, 2-ii, 3-iii, 4-iv Table II

(i) Bifocal lens

(ii) Cylindrical lens

(iii) Concave lens

(iv) Convex lens

(2) 1-iv, 2-iii, 3-i, 4-ii

(4) 1-ii, 2-iv, 3-i, 4-iii

[AIIMS 2000]

Q.3 A light wave moves from air to glass with frequency \(v\) and wavelength \(\lambda\). Then [AIIMS 2000]

(1) \(v\) changes

(2) \(u\) does not change, \(\lambda\) change.

(3) \(\lambda\) does not change

(4) \(v\) and \(\lambda\) changes

Q.4 A good photographic print is obtained by an exposure of 2 second at a distance of \(1 \mathrm{~m}\) from the lamp. How much time will be required to get equally good result at a distance \(2 \mathrm{~m}\) from the same lamp?

(1) 1 second

(2) 2 second

(3) 4 second

(4) 8 second

[AIIMS 2000]

Q.5 The Cauchy's dispersion formula is

(1) \(\mathrm{n}=\mathrm{A}+\mathrm{B} \lambda^{-2}+\mathrm{C} \lambda^{-4}\)

(2) \(\mathrm{n}=\mathrm{A}+\mathrm{B} \lambda^{-2}+\mathrm{C} \lambda^{4}\)

(3) \(\mathrm{n}=\mathrm{A}+\mathrm{B} \lambda^{2}+\mathrm{C} \lambda^{-4}\)

(4) \(n=\mathrm{A}+\mathrm{B} \lambda^{2}+\mathrm{C} \lambda^{4}\)

[AIIMS 2002]

Q.6 Brilliance of diamond is due to

(1) shape

(2) reflection

(3) cutting

(4) total internal reflection

[AIIMS 2002]

Q.7 When a beam of light is used to determine the position of an object, the maximum accuracy is achieved if the light is

(1) polarised

(2) of longer wavelength

(3) of shorter wavelength

(4) of high intensity

[AIIMS 2003]

Q.8 In an experiment to find the focal length of a concave mirror a graph is drawn between the magnitudes of \(u\) and \(v\). The graph looks like

[AIIMS 2003]

Q.9 Sodium lamps are used in foggy conditions because

GEOMETRICAL OPTICS

[AIIMS 2004]

(1) yellow light is scattered less by the fog particles

(2) yellow light is scattered more by the fog particles

(3) yellow light is unaffected during its passage through the fog

(4) wavelength of yellow light is the mean of the visible part of the spectrum.

Q.10 An object is immersed in a fluid. In order that the object becomes invisible, it should.

(1) Bahave as a perfect reflector

[AIIMS 2004]

(2) Absorb all light falling on it

(3) Have refractive index one

(4) Have refractive index exactly matching with that of the surrounding fluid

Q.11 A telescope has an objective lens of focal length \(200 \mathrm{~cm}\) and an eye piece with focal length \(2 \mathrm{~cm}\). If this telescope is used to see a 50 meter tall building at a distance of \(2 \mathrm{~km}\), what is the height of the image of the building formed by the objective lens

(1) \(5 \mathrm{~cm}\)

(2) \(10 \mathrm{~cm}\)

(3) \(1 \mathrm{~cm}\)

(4) \(2 \mathrm{~cm}\)

[AIIMS 2005]

Q.12 What should be the maximum acceptance angle at the air-core interface of an optical fibre if \(\mathrm{n}_{1}\) and \(\mathrm{n}_{2}\) are the refractive indices of the core and the cladding, respectively

[AIIMS 2005]

(1) \(\sin ^{-1}\left(n_{2} / n_{1}\right)\)

(2) \(\sin ^{-1} \sqrt{n_{1}^{2}-n_{2}^{2}}\)

(3) \(\left[\tan ^{-1} \frac{\mathrm{n}_{2}}{\mathrm{n}_{1}}\right]\)

(4) \(\left[\tan ^{-1} \frac{\mathrm{n}_{1}}{\mathrm{n}_{2}}\right]\)

Q.13 A lens is made of flint glass (refractive index \(=1.5\) ). When the lens is immersed in a liquid of refractive index \(1 \cdot 25\), the focal length

(1) Increases to a factor of \(1 \cdot 25\)

(2) Increases to a factor of \(2 \cdot 5\)

(3) Increases to a factor of \(1 \cdot 2\)

(4) Decreases to a factor of \(1 \cdot 2\)

[AIIMS 2006]

Q.14 The camera lens has an aperture of \(f\) and the exposure times is \((1 / 60) \mathrm{s}\). What will be the new exposure time if the aperture become \(1.4 \mathrm{f}\) ?

[AIIMS 2007]

(1) \(\frac{1}{42}\)

(2) \(\frac{1}{56}\)

(3) \(\frac{1}{72}\)

(4) \(\frac{1}{31}\)

Q.15 A point source is kept at a distance of \(1000 \mathrm{~m}\) has an illumination I. To change the illumination to \(16 \mathrm{I}\) the new distance should become

(1) \(250 \mathrm{~m}\)

(2) \(500 \mathrm{~m}\)

(3) \(750 \mathrm{~m}\)

(4) \(800 \mathrm{~m}\)

[AIIMS 2007]

Q.16 The focal length of the objective and eye lenses of a microscope are \(1.6 \mathrm{~cm}\) and \(2.5 \mathrm{~cm}\) respectively. The distance between the two lenses is \(21.7 \mathrm{~cm}\). If the final image is formed at infinity. What is the linear magnification?

(1) 11

(2) 110

(3) 1.1

(4) 44

[AIIMS 2007]

Q.17 A converging lens forms a real image I of an object on its principal axis. A rectangular slab of refractive index \(\mu\) and thickness \(\mathrm{x}\) is introduced between I and the lens, I will move

[AIIMS 2008]

(1) towards the lens \((\mu-1) \mathrm{x}\)

(2) towards the lens by \(\left(1-\frac{1}{\mu}\right) x\)

(3) away from the lens by \((\mu-1) x\)

(4) away from the lens by \(\left(1-\frac{1}{\mu}\right) \mathrm{x}\) Q.18 Lumen is the unit of

(1) luminous flux

(2) luminosity

(3) illumination

(4) quantity of light

GEOMETRICAL OPTICS

[AIIMS 2008]

Q.19 When white light passes through a prism, the deviation is maximum for

(1) violet light

(2) green light

(3) red light

(4) yellow light

[AIIMS 2008]

Q.20 An object \(5 \mathrm{~cm}\) tall is placed \(1 \mathrm{~m}\) from a concave spherical mirror which has a radius of curvature of 20 \(\mathrm{cm}\). The size of the image is

(1) \(0.11 \mathrm{~cm}\)

(2) \(0.50 \mathrm{~cm}\)

(3) \(0.55 \mathrm{~cm}\)

(4) \(0.60 \mathrm{~cm}\)

[AIIMS 2008]

Q.21 The magnifying power of a compound microscope increases with

[AIIMS 2008]

(1) the focal length of objective lens is increased and that of eye lens is decreased

(2) the focal length of eye lens is increased and that of objective lens is decreased

(3) focal lengths of both objects and eye-piece are increased

(4) focal lengths of both objects and eye-piece are decreased.

Q.22 A convex lens of refractive index \(\frac{3}{2}\) has a power of \(2.5 \mathrm{D}\) in air. If it is placed in a liquid of refractive index 2 , then the new power of the lens is

(1) \(-1.25 \mathrm{D}\)

\((2)-1.5 \mathrm{D}\)

(3) \(1.25 \mathrm{D}\)

(4) \(1.5 \mathrm{D}\)

[AIIMS 2009]

Q.23 Light with an energy flux of \(18 \mathrm{~W} / \mathrm{cm}^{2}\) falls on a non-reflecting surface at normal incidence. The pressrue exerted on the surface is

[AIIMS 2009]

(1) \(2 \mathrm{~N} / \mathrm{m}^{2}\)

(2) \(2 \times 10^{-4} \mathrm{~N} / \mathrm{m}^{2}\)

(3) \(6 \mathrm{~N} / \mathrm{m}^{2}\)

(4) \(6 \times 10^{-4} \mathrm{~N} / \mathrm{m}^{2}\)

Q.24 In a concave mirror, an objective is placed at a distance \(d_{1}\) from the focus and the image is formed at a distance \(d_{2}\) from the focus. Then the focal lengths of the mirror is

[AIIMS 2009]

(1) \(\sqrt{\mathrm{d}_{1} \mathrm{~d}_{2}}\)

\((2) d_{1} d_{2}\)

(3) \(\left(d_{1}+d_{2}\right) / 2\)

(4) \(\sqrt{d_{1} / d_{2}}\)

Q.25 A short linear object, of length \(l\), lies along the axis of a concave mirror, of focal length \(\mathrm{f}\), at a distance \(\mathrm{d}\) from the pole of the mirro. The size of the image is then (nearly)

[AIIMS 2009]

(1) \(\frac{l f}{d-f}\)

(2) \(\frac{d-f}{l f}\)

(3) \(l \frac{\mathrm{f}^{2}}{(\mathrm{~d}-\mathrm{f})^{2}}\)

(4) \(\frac{(\mathrm{d}-\mathrm{f})^{2}}{\mathrm{f}^{2}} l\)

Q.26 The near point is \(100 \mathrm{~cm}\) for a man. To see the distant object clearly, what is the power of required lens?

(1) \(-1 \mathrm{D}\)

\((2)+1 \mathrm{D}\)

(3) \(-3 \mathrm{D}\)

(4) \(+3 \mathrm{D}\)

[AIIMS 2010]

Q.27 Achromatic combination of lenses comprises of the two lenses of same material placed \(4 \mathrm{~cm}\) apart. If focal length of one lens is \(5 \mathrm{~cm}\), the focal length of other lens is :

(1) \(2 \mathrm{~cm}\)

(2) \(4 \mathrm{~cm}\)

(3) \(6 \mathrm{~cm}\)

(4) \(3 \mathrm{~cm}\)

[AIIMS 2010]

Q.28 Two lens of focal length \(-20 \mathrm{~cm}\) and \(+10 \mathrm{~cm}\) are put in combination, find the power of the combination:

(1) \(-1 \mathrm{D}\)

\((2)-2 \mathrm{D}\)

\((3)+5 \mathrm{D}\)

\((4)+2 \mathrm{D}\)

[AIIMS 2011]

Q.29 A far sighted person has his near point \(50 \mathrm{~cm}\), find the power of lens he should use to see at \(25 \mathrm{~cm}\), clearly:

(1) +1

\((2)+2\)

(3) -2

(4) \(-1 \mathrm{D}\)

[AIIMS 2011] Q.30 In a convex lens of focal length \(\mathrm{F}\), the minimum distance between an object and its real image must be :-

[AIIMS 2012]

(1) \(3 \mathrm{~F}\)

(2) \(4 \mathrm{~F}\)

(3) \(\frac{3}{2} \mathrm{~F}\)

(4) \(2 \mathrm{~F}\)

Q.31 A light ray is incident on a glass slab, it is partially reflected and partially transmitted. Then the reflected ray is :-

(1) Completly polarised and highly intense

(2) Partially polarised and poorly intense

(3) Partially polarised and highly intense

(4) Completly polarised and poorly intense

Q.32 The frequency of a light wave in a material is \(2 \times 10^{14} \mathrm{~Hz}\) and wavelength is \(5000 \AA\). The refractive index of material will be

(1) 1.50

(2) 3.00

(3) 1.33

(4) 1.40

[AIIMS 2013]

Q.33 The length of deviation for a glass prism is equal to its refracting angle. The refractive index of glass is 1.5. Then the angle of prism is

(1) \(2 \cos ^{-1}(3 / 4)\)

\((2) \sin ^{-1}(3 / 4)\)

(3) \(2 \sin ^{-1}(3 / 2)\)

(4) \(\cos ^{-1}(3 / 2)\)

[AIIMS 2014]

Q.34 The near point of distinct vision is at \(1 \mathrm{~m}\) for an elderly person. What power of lens is to be used to bring the near point to the minimum distance of distinct vision \((25 \mathrm{~cm})\) ?

(1) \(2.5 \mathrm{D}\)

(2) \(3 \mathrm{D}\)

(3) \(3.5 \mathrm{D}\)

(4) \(4 \mathrm{D}\)

[AIIMS 2014]

Q.35 A person uses \(+1.5 \mathrm{D}\) glasses to have normal vision from \(25 \mathrm{~cm}\) onwards. he uses a \(+20 \mathrm{D}\) lens as a simple microscope to see an object. What is the maximum magnifying power if he uses the microscope without glasses?

(1) 8

(2) 9

(3) 10

(4) 11

[AIIMS 2015]

Q.36 Light wave enters from medium 1 to medium 2. Its velocity in \(2^{\text {nd }}\) medium is double from \(1^{\text {st }}\). For total internal reflection the angle of incidence must be greater than

(1) \(30^{\circ}\)

(2) \(60^{\circ}\)

(3) \(45^{\circ}\)

\(\left(490^{\circ}\right.\)

[AIIMS 2016]

Q.37 A transparent cube of \(15 \mathrm{~cm}\) edge contains a small air bubble. Its apparent depth when viewed through one face is \(6 \mathrm{~cm}\) and when viewed through opposite face is \(4 \mathrm{~cm}\). The refractive index of material of cube is

(1) 2.0

(2) 1.5

(3) 1.6

(4) 2.5

[AIIMS 2016]

Q.38 Focal length of objective and eye piece of telescope are \(200 \mathrm{~cm}\) and \(4 \mathrm{~cm}\) respectively. What is the length of telscope for normal adjustment?

(1) \(196 \mathrm{~cm}\)

(2) \(204 \mathrm{~cm}\)

(3) \(250 \mathrm{~cm}\)

(4) \(225 \mathrm{~cm}\)

[AIIMS 2016]

Q.39 For a situation shown in figure, find the refractive index of glas so that it will suffer total internal reflection at the vertical surface

(1) 1.732

(2) 1.5

(3) 1.31

(4) 1.6

[AIIMS 2016]

Q.40 A \(2.0 \mathrm{~cm}\) tall object is placed \(15 \mathrm{~cm}\) in fron of a concave mirror of focal length \(10 \mathrm{~cm}\). What is the size and nature of the image?

(1) \(4 \mathrm{~cm}\), real

(2) \(4 \mathrm{~cm}\), virtual

(3) \(1.0 \mathrm{~cm}\), real

(4) none of these Q.41 The least distance of vision of a longsighted person is \(60 \mathrm{~cm}\). By using a spectacle lens, this distance is reduced to \(12 \mathrm{~cm}\). The power of the lens is

\((1)+5.0 \mathrm{D}\)

\((2)+(20 / 3) D\)

(3) \(-(10 / 3) \mathrm{D}\)

\((4)+2.0 \mathrm{D}\)

[AIIMS 2017]

Q.42 In a simple microscope of focus lenvgth \(5 \mathrm{~cm}\) final image is formed at \(\mathrm{D}\), then its magnification will be :

(1) 6

(2) 5

(3) 2

(4) 1

[AIIMS 2018]

Directions for Assertion and Reason questions :

(A) If both Assertion and Reason are true and the Reason is the correct explanation of the Assertion.

(B) If both Assertion and Reason are true but Reason is not the correct explanation of the Assertion.

(C) If Assertion is true but Reason is false.

(D) If the Assertion and Reason both are false.

Q.43 Assertion : Danger signals are made of red colour.

Reason : Velocity of red light is maximum and thus more visibility in dark.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.44 Assertion : Endoscopy involves use of optical fibres to study internal organs

[AIIMS 2000]

Reason : Optical fibres are based on phenomena of toal internal reflection.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) D

[AIIMS 2000]

Q.45 Assertion : If a convex lens is kept in water its convergent powr decreases.

Reason : Focal length of convex lens in water increases.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.46 Assertion : The stars twinkel while the planets do not.

Reason : The stars are much bigger in size than the planets.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2000]

Q.47 Assertion : Owls can move freely during night.

Reason : They have large number of rods on their retina.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2003]

Q.48 Assertion : A red coloured object appears dark in the yellow light.

Reason : The red colour is scattered less.

(1) \(\mathrm{A}\)

(2) B

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2003]

Q.49 Assertion : By roughening the surface of a glass sheet its transparency can be reduced.

Reason : Glass sheet with rough surface absorbs more light.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) D

[AIIMS 2004]

Q.50 Assertion : Diamond glitters briliantly.

Reason : Diamond does not absorb sunlight.

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) D

[AIIMS 2005]

Q.51 Assertion : Optical fibres are used for telecommunication.

[AIIMS 2007]

Reason : Optical fibres are based on the phenomenon of total internal reflecton.

(1) A

(2) B

(3) \(\mathrm{C}\)

(4) D Q.52 Assertion : Goggles have zero power.

Reason : Radius of curvature of both sides of lens is same.

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2007]

Q.53 Assertion : The colour of the green flower seen through red glass appears to be dark.

Reason : Red glass transmits only red light.

(1) A

(2) \(B\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2008]

Q.54 Assertion : A double convex lens \((\mu=1.5)\) has focal length \(10 \mathrm{~cm}\). When the lens is immersed in water \((\mu=4 / 3)\) its focal length becomes \(77 \mathrm{~cm}\).

\(\operatorname{Reason}: \frac{1}{f}=\frac{\mu_{v}-\mu_{m}}{\mu_{m}}\left(\frac{1}{R_{1}}-\frac{1}{R_{2}}\right)\)

[AIIMS 2008]

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.55 Assertion : A total reflecting prism is used to erect the inverted image without deviation. Reason : Rays of light incident parallel to base of prism emerge out as parallel rays.

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) D

[AIIMS 2009]

Q.56 Assertion : If objective and eye lenses of a microscope are interchanged then it can work as telescope. Reason : The objective lens of telescope has small focal length.

(1) \(\mathrm{A}\)

(2) \(B\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2010]

Q.57 Assertion : When white light fall on the compact disc, multicolours are seen after reflection.

Reason : CD disc behaves like a prism.

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2011]

Q.58 Assertion : When a white light is passed through a lens, violet light is more refracted than red light. Reason : Focal length for red light is greater than violet.

(1) \(\mathrm{A}\)

(2) B

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2011]

Q.59 Assertion : Microscope magnifies the image.

Reason : Angular magnification for image is more than object in microscope. [AIIMS 2011]

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.60 Assertion : Magnification of a convex mirror is always positive, but that of a concave mirror may be both positive or negative.

Reason : It depends on the sign convention chosen.

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2011]

Q.61 Assertion : A thick lens shows more chromatic aberration.

Reason : Thick lens behave as many thin lenses.

(1) \(A\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) D

[AIIMS 2012]

Q.62 Assertion : If optical density of a substance is more than that of water then the mass density of substance can be less than water.

Reason : Optical density and mass density are not related.

(1) \(A\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\) Q.63 Assertion: The sun rises some time before the actual sun-rise.

GEOMETRICAL OPTICS

[AIIMS 2013]

Reason : During sun rises, the refraction takes place through the different layers of atmosphere.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.64 Assertion : The edge of the image of white object formed by a concave mirror on the screen appear white.

[AIIMS 2009, 2014]

Reason : Concave mirror does not suffer from chromatic aberration.

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.65 Assertion : In optical fibre, the diameter of the core is kept small.

[AIIMS 2015]

Reason : The smaller diameter of the core ensures that the fibres should have incident angle more than the critical angle required for total internal reflection.

(1) A

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.66 Assertion : A secondary rainbow have inverted colours than the primary rainbow. [AIIMS 2015] Reason : The secondary rainbow is formed by single total internal reflection.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.67 Assertion : When an object is placed between two plane parallel mirrors, then all the images found are of equal intensity.

Reason : In case of plane parallel mirrors, only two images are possible.

(1) \(\mathrm{A}\)

\((2) \mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

[AIIMS 2016]

Q.68 Assertion : A ray of light is incident from outside on a glass sphere surrounded by air. This ray may suffer total internal reflection at second interface.

[AIIMS 2017]

Reason : If a ray of light goes from denser to rarer medium, it bends away from the normal.

(1) \(\mathrm{A}\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) \(\mathrm{D}\)

Q.69 Assertion : Rainly clouds appear dark from below.

[AIIMS 2018]

Reason : Ther is not sufficint light which can be scattered by these clouds.

(1) \(A\)

(2) \(\mathrm{B}\)

(3) \(\mathrm{C}\)

(4) D