Geometrical Optics Questions and Answers

7 Fixed Mirror A plane mirror of semicircular shape radius 1m is placed in y z plane with its diamete a distance of 10 m from plane mirror there is a wall also parallel to y z plane The ratio along y axis and centre at origin An object is placed on the axis of mirror at point 5 0 0 area of spot of light on wall to that of mirror is 1 Im Sm A Bound with wolumetric expansion coefficient 200 x 10 C and bulk modulus 1 2 x 10 Ai 3

Then If t 1 and English U of refractive index along the line y 8 incident on the interface of a medium of refractive index whose curve is given by y 16x 142 2 then angle of deviation is 71 12 5T If 1 and 2 2 then angle of deviation is 12 EN X lew

Identify the wrong description of the given figures 1 2 3 1 Question Type Single Correct Type 2 3 F A F 4 1 represents far sightedness 2 represents correction for short sightedness 3 represents far sightedness 4 represents correction for

An air bubble is inside water The refractive index of water is 4 3 At what distance from the air bubble should a point be placed so as form a real image at the same distance from the bubble Question Type Single Correct Type 1 2R 2 3R 3 4R 4 the air bubble cannot form

O D Two transparent media of refractive indices andu have a solid lens shaped transparent material of refractive index between them as shown in figures in Column II A ray traversing these media is also shown in the figures In Column I different relationships between and are given Match them to the ray diagram shown in Column II Column II A B C D Column I Hi H H H H H3 H H3 A q 1 A s r A p 1 p q H3 H42 r s H3 B q s t B p s t B q s t 141 143 143 H1 141 I I 141 C p 1 t C q 1 t C p 1 t D P D 1 D q

An object and its real image are located at distances 25 cm and 40 cm respectively from the two principal focii of a convex lens The linear magnification of the image is near to 1 1 3 2 1 3 3 1 8 4 1 8

SolveLancer Test The difference between the object distance and image distance is 10 cm Magnification of the image is 2 Find the focal length of the lens and also which type of lens is used SolveLancer Test a 10 cm b 10 cm c 20 cm d 20 cm

For an object placed at 20 cm in front of a convex lens the image is at distance 30 cm behind the lens If lens is replaced by concave lens of same focal length then for same object distance image formed will be

Example 46 The refractive indices of flint glass for red and violet light are 1 613 and 1 632 respectively Find the angular dispersion produced by the thin prism of flint glass having refracting angle 5

Example 47 White light is passed through a prism of angle 5 If the refractive indices for red and blue colours are 1 641 and 1 659 respectively calculate the angle of deviation between them also calculate the dispersive power

A longsighted person has a minimum distance of distinct vision of 75 cm He wants to reduce to 25 cm The person should use a Converging lens with power 2 D Converging lens with power 2 67 D Diverging lens with power 2 D Diverging lens with power 2 67 D

A light ray travels in a liquid through gas bubble and goes into the liquid again as shown in the figure Which of the following situations is possible when the torch is shifted higher Light ray A C Light ray Light ray J Light ray B H D Light ray e

49 The path of a ray of light coming from air passing through a rectangular glass slab traced by four students are shown as A B C and D in figure Which one of them is correct A Fig A B Fig B C Fig C D Fig D D

For the system shown in figure at t 0 sharp image is formed on the screen Now the screen is removed and the lens starts moving with speed v to the right at t 0 If average velocity of the image over the time interval t 0 to t 5 s is zero then find the value of speed v of the lens in cm s 45 cm f 30 cm V Screen

A bird flies downward approaching a swimming pool To a diver in the pool inside the water the bird will appear to Move faster than its actual speed Move slower than its actual speed Move with the actual speed

The arrangement shows a point object O placed on the axis of a thin convex lens of focal length f 20 cm A sharp image is obtained behind the lens It is found that if O is displaced along a line perpendicular to axis by a distance of 1 cm moves by 2 cm Answer the following questions f 20 cm B B axis 22 If the object is displaced by 0 01 cm towards C along axis of the lens I moves 1 Away from C along the axis by 0 02 cm 3 Away from C along the axis by 0 04 cm 2 Towards C along the axis by 0 02 cm 4 Towards C along the axis by 0 04 cm

SolveLancer Test Consider two convex lens as in figure i 14 FFF 14 ii 1 1 The focal lengths and number of images formed from these two combinations are SolveLancer Test a f 1 3 f ii 2 and images are I i ii 2 b f 1 1 f t 1 and images are I i 1 c f 3 f 1 and images are 11 3 I 1 d fo f n 2 and images are l 1 1 2

5 A concave mirror gives an image two times as large as the object placed at a distance of 30 cm from it For the image to be real the focal length should be 1 10 cm 2 15 cm 4 20 cm 3 30 cm

A swimming pool is filled with water up to its brim A swimmer observes a source of light just over the edge of the pool looking from a depth of 2 m in water and at a dis tance of 1 5 m from the vertical wall of the pool The source of the light is placed at a height of 3 m from the ground and at a distance of 4 m from the edge of the pool Find the refractive index of water in the swimming pool 4

Refraction at spherical interface Refraction through lens A ray of light is incident on a glass sphere at an angle o Angle of refraction at the surface on which it is incident is B What is the angle by which the ray is deviated as it comes out of the sphere 2 B The minimum distance between a point object and its real image formed by a convex lens of focal length fis

Figure shows a mixture of blue green and red 1 coloured rays incident normally on a right angled prism The critical angles of the material of the prism for red green and blue are 46 44 and 43 respectively The arrangement will separate B G R 43 44 46 459 1 Green colour from red and blue 2 All the three colurs 3 Red colour from blue and green 4 Blue colour from red and green eller at afford fo 4 46 44 3 que atom figura dat fa fa mi B G R 43 46 1 2 3 4 43 4 2 45

The vertical displacement of light rays parallel to the axis of a lens is measured as a function of the vertical displacement h of the incident ray from the principal axis a shown in the figure a The data is plotted in figure b The distance D from the lens to the screen is 1 0 m If the focal length of the lens for paraxial rays is 10 K c then what is K Screen 1 lens D Figure a d cm NO 2 2 1 h cm Figure b

incident is What is the angle by which the ray is deviated as it comes out of the sphere 1 The minimum distance between a point object and its real image formed by a convex lens of focal length fi 1 2 2 4t 3 1 9 4 f

6 At what distance from a convex lens of focal length 30 cm an object should be placed so that the size of image be half of object 30 cm 3 1 30 cm d bad du fui y v deg vei fi fou f und ufafa 3 15 cm 2 60 cm 4 90 cm

A normal eye is not able to see objects closer than 25 cm because 1 the focal length of the eye is 25 cm 2 the distance of the retina from the eye lens is 25 cm 3 the eye is not able to decrease the distance between the eye lens and the retina beyond 4 the eye is not able to decrease the focal length beyond a limit

I was standing infront of a mirror and I wass seeing the objects that were infro nt of the mirror but when I turned my he ad to the right I could see the objects th at are in the left corner of my room ho w foes this happens

A ray of light enters into a thick glass slab from air as shown in figure The refractive index varies as 2 3 y If width of slab is very large then maximum value of y coordinate of the ray is ty X

Plane polarised light is passed through a 6 polaroid On viewing through the polariod we find that when the polariod is given one complete rotation about the direction of the light one of the following is observed 1 The intensity of light gradually decreases to zero and remains at zero 2 The intensity of light gradually increases to a maximum and remains at maximum 3 There is no change in intensity 4 The intensity of light is twice maximum and twice zero a f y yo te and fem 1 fa fat 2 fa uff efft ad fu effe 3 kada i stan 4 at an aftra funduva at ang i

20 A converging lens and a diverging lens share the same principal axis Their focal lengths are f f respectively What should be the distance between them so that a beam parallel to principal axis emerges parallel to principal axis f 07

2 The reason of seeing the Sun a little before the sunrise is MP PMT 2001 Odisha JEE 2003 b Refraction of the light d Dispersion of the light a Reflection of the light c Scattering of the light

A thin glass slab of thickness t and refractive index H is inserted between an object O and an observer both of which are in a medium of refractive index Calculate the shift for the given object O ICI H eve

Light of wavelength 6000 falls on a plane reflecting surface in vacuum Frequency and wavelength of the reflected light will be O 6000 6 1014 Hz 6000 5 10 4 Hz 5000 6 x 10 5 Hz min s 5000 5 x 10 5 Hz

In the expression for resolving limit of a 1 22 2 sin microscope d called min the product usin is also Objective aperture O Fresnel distance

Assume that light of wavelength 7500 is coming from a star What is the limit of resolution of a telescope whose objective has a diameter of 150 inch 1 inch 2 54 cm 0 8 x 10 7 rad 2 4 x 10 7 rad 3 2 x 10 7 rad 18 x 10 7 rad

20 68 7 m For what distance is ray optics a good approximation when the aperture is 4 mm wide and the wavelength is 450 nm 42 7 m Mark for Review 35 5 m 29 3 min se

Who gave the corpuscular model of light and derived Snell s law O Newton Descartes min se Huygens

Plane glass slab is kept between a model and a plane mirror The mirror is 50 cm away from the model The glass slab has a thickness of 15 cm and refractive index of 1 5 At what distance in cm from herself will the model see her image 1 40 3 80 2 50 4 90

Parallel rays of light are focused by a thin convex lens A thin concave lens of same focal length is then joined to the convex lens and the result is that A The focal point shifts away from the lens by a small distance B The focal point shifts towards the lens by a small distance C The focal point does not shift at all D The focal point shifts to infinity Choose the correct answer below

6 There is a medium has refractive index and 3 3 another medium 2 has refractive index 2 refractive index of medium 2 with respect to medium 1 will be 1 9 10 2 10 3 52 4 The 2 5

A ray of light is incident at an angle of 60 on one face of a prism of angle 30 The emergent ray of light makes an angle of 30 with incident ray The angle made by emergent ray with second face of prism will be 1 0 2 90 3 45

If oil film of uniform thickness t is formed on water Refractive index of oil is more than water A Monochromatic light of wavelength is incident normally on the oil film The condition for dark fringe in reflected light is consider m as integer in following options A 02 it mx B 02 t m C O2 t m 12 1 D 02 t m 1

The forward base safe operating area pertains to O The transistor operation when base collector junction is forward biased to turn on the transistor The transistor operation when base emitter junction is forward biased to turn off the transistor O The transistor operation when base emitter junction is reverse biased to turn on the transistor The transistor operation when base emitter junction is forward biased to turn on the transistor

A point object O can undergo freefall motion along vertical line AB as shown in igure The mirror is vertical plane mirror When image of the object is first visible to D then it is released at t 0 from rest from A The time for which image is visible to D is given by NIT D NIT 2 d 3L u 0 3L 19 a

A spherical surface separates air medium for which 1 615 for violet and u 1 600 for red color A paraxial beam parallel to optic axis is incident on the surface as shown The distance between point of convergence for violet and red color is Af air 10cm A Af 0 41 cm B Point of convergence for red is closer to optical centre than that for violet C Point of convergence for violet is closer to optical centre than that for red D Af 0 84 cm

15 O 5 m 5 m En X lish En A plane mirror is placed on x z plane and is free to rotate about z axis A fixed object is on x y plane at a point 0 5 m 5 m When mirror starts rotating anticlockwise with angular speed 5 rad s about z axis The initial linear speed of image is Review

A ray of light is incident on a prism at surface AB Side AB AC are equal and base BC is silvered then find net angle of deviation of emergent ray with respect to incident ray 1 Question Type Single Correct Type 2 3 45 90 B 60 H

A ray of light falls on a transparent sphere as shown in the figure If the final ray emerges from the sphere parallel to the horizontal diameter then calculate the refractive index of the sphere Consider that the sphere is kept in air o Question Type Single Correct Type 1 2 1 5 2 600 4

Name of the Student Note Tie up this paper to main answer sheet Instructions i Answer all the questions ii Each answer has four alternatives Select the right one from them iii Each answer carries 1 mark SECTION IV 1 Which of the following mirrors is used as rear view mirror A Concave mirror B Convex mirror C Plane mirror D Converging mirror 2 Which of the following is used to make surfaces smooth A CaSO4 H O C CaOC A 0 15 cm C 25 40 cm B Na CO3 D NaOH 3 Raju observed inverted diminished real image on the screen using concave mirror of focal length 15 cm The image distance would be in between A CO C NO Roll No B 15 30 cm D 30 45 cm 4 In an experiment evolved gas is passed through lime water and formed white precipitate The gas evolved is B SO D CO 10 x 1 10 1

In a compound microscope the object is 1 cm from the objective lens The lenses are 30 cm apart and the intermediate image is 5 cm from the eyepiece The magnification produced is assume normal adjustment 100 125 60

Chromatic aberration refers to Difference between refractive index of lens material and the surrounding When white light passes through thick lenses red and blue colours focus at different points Different power of a lens for paraxial and marginal rays All of the above