Geometrical Optics Questions and Answers

Two plane mirror are inclined at an angle of 60 as shown in figure A ray of light incident on one mirror is parallel to the other What will be the angle between the first incident ray and last reflected ray A 120 C 30 60 M M B 60 D 0

GO0074 5 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

A terrestrial telescope is made by introducing an inverting lens of focal length fi The focal length of objective and eyepiece are fo and fe Then the length of the telescope for normal adjustment is 1 fo fe fi 2 fo fe 2 fi 3 2fo fe fi 4 fo fe 4 fi

Three right angled prisms of refractive indices 2 and 3 are fitted together as shown in the figure If a ray passes through the prisms without suffering any deviation then find the relation between the three refractive indices of the prisms Ans 1 3 B 3 a Le P 4 2 Q C R P3 S E

The angle of polarisation for any medium is 60 what will be the criticle angle for this medium at air interface Question Type Single Correct Type 3 2 sin 3 3 cos 3 1 sin 1

A man with hypermetropia cannot see objects closer than a distance of 40 cm from the eye The power of the lens required so that he can see objects at 25 cm from the eye is 1 4 5D 2 4 0D 3 1 5D 4 3 0D

number of identical equilateral prism are kept in contact as shown in figure If deviation through a single prism is The m are integers If n 2m deviation through n prisms is zero If n 2m 1 deviation through system of n prisms is d If n 2m deviation through system of n prisms is d If n 2m 1 deviation through system of n prisms is zero

The angle of incidence for a ray of light at a refracting surface of a prism is 45 The angle of prism is 60 If the ray suffers minimum deviation through the prism the angle of minimum deviation and refractive index of the material for the prism respectively are A 45 2 C 45 B 30 D 30 1 IS IS 2 1 2 4

Two concave mirror of focal length f and f2 are placed facing each other and d distance apart Find the value of dmin If object is placed between the mirrors that object and image will coincide f f 2f 2f f 2f 2f f2 Solution M Correct Answer My Answer

An object moving at a speed of 5 m s towards a concave mirror of focal length f Im is at a distance of 9m The average speed of the image approximately 1 3 4 m s 1 10 STOLE Correct Answer 1 Status unattempted m s m s m s

14 For the given incident ray as shown in figure the condition of total internal reflection of the will be satisfied if the refractive index of block will be 1 3 3 1 2 3 To 45 Incident ray 2 1 2 2 4 7

A thin plano convex lens of refractive index 1 5 is kept such that medium on its convex side is air 1 and on its plane side is a medium of refractive index 13 It is given that the image is formed at position I at a distance from the plane side of the lens It is also given that R v 3 1 8 where it is the distance of object OO from the lens as shown R is the radius of curvature of convex side of the lens and vis distance of image Hy Find the size of image if size of object is 1 cm Hy

A point object O is placed at the origin a thin equi convex glass lens refractive index of glass is 1 5 and its focal length in air medium is 20cm and placed so that its principal axis along x axis Now the lens is cut at the middle along the principal axis and upper half is shifted along x axis and y axis by 20cm and 2mm respectively and right side of lower half is filled with water u 4 3 as shown in figure then find the difference in y coordinate of the images formed by the upper half and lower half in mm W Y in mm Air Air Air Water 2mm X in cm

A quarter cylinder of radius R and refractive index 1 5 is placed on two sides of a table A point object P is kept at a distance of mR from it If the value of m for which a ray from P will emerge parallel to the table as shown in figure X is 3 then find the value of x the distance between two half is 0 01 cm 0 01cm

The radius of curvature of the left and right surface of the concave lens are 10 cm and 15 c respectively The radius of curvature of the mirror is 15 cm Air Glass 3 2 Water u 4 3 A equivalent focal length of the combination is 18 cm B equivalent focal length of the combination is 36 cm C the system behaves like a concave mirror D the system behaves like a convex mirror

Q 15 4 1 O If i denotes a unit vector along incident light ray a unit vector along refracted ray into a medium of refractive index and n unit vector normal to boundary of medium directed towards incident medium then law of refraction is O i n r n 00 08 ix

Calculate the critical angle for glass air interface if a ray of light incident on a glass surface is deviated through 15 when angle of incidence is 45 Sir yahan pein samjhe kaise ki kis medium mein incidence ho raha hain

If a luminous object is placed in front of a thick glass mirror several images are formed due to multip reflections The second image formed by the first reflection by the polished surface is much brighter tha the others The intensity of the other images rapidly fade away

A ray of light is incident at 50 on the middle of one of the two mirrors arranged at an angle of 60 between them The ray then touches the second mirror gets reflected back to the first mirror making an angle of incidence O 50 60

What is the angle of incidence for an equilateral prism of refractive index 3 so that the ray is parallel to the base inside the prism O 30 O 45 LO 60 Either 30 or 60

14 In a compound microscope the focal length of two lenses are 1 5cm and 6 25 cm If an object is placed at 2cm from objective and final image is formed at 25cm from eye lens the distance between the two lenses is 1 6cm 3 9 25cm 2 7 75cm 61 4 11cm

85 Two lenses are placed in contact with each other and the focal length of combination is 80 cm If the focal length of one is 20 cm then the power of the other will be a 1 66 D c 1 00 D b 4 00 D d 3 75 D 86 A ray of light falls on a denser rarer boundary from denser side The critical angle is 45 The maximum deviation the ray can undergo is b 45 a 30 c 90 d 120 87 A plano convex lens of refractive index 1 5 and radius of curvature 30 cm is silvered at the curved surface Now the lens has been used to form the c f 92 A concave lens o contact with a pl a convex mirror b concave mirror c concave mirro d concave mirro

26 A screen is placed 90 cm from an object The image of the object on the screen is formed by a convex lens at two different locations separated by 20 cm Determine the focal length of the lens a 21 4 cm c 214 cm b 2 14 cm d 0214 cm

In figure a point object O is placed in air A spherical boundary separates two media AB is the principal axis The refractive index above AB is 1 6 and below AB is 2 0 The separation between the images formed due to refraction at the spherical surface is 1 12 m 2 m 1 6 2 0 2 20 m B

A fish rising vertically up towards the surface of water with speed 3 ms and a bird diving vertically downwards with speed velocity of bird with respect to fish is water 4 3 15 ms

A equiconvex lens has a focal length f and power P It is cut into two symmetrical halves by a plane normal to shown in figure i The two pieces are recombined as shown in figure ii Then the power of the combination is OD DO i ii Zero P 2

Q 3 4 1 00 15 A biconvex lens form a real image of an object placed perpendicular to its principal axis Suppose the radii of curvature of the lens tend to infinity Then the image would O Disappear O Remain as real image still Be virtual and of the same size as the object 000

What must be the angle of the flint glass prism g By joining prism of two different glasses shown in the figure it is possible to obtain deviation without dispersion We then say that the prism is achromatic It is required to fit a 5 crown glass prism with a flint glass prism so as to achromatize the wavelength interval between the C and F spectra lines The D line is located in the yellow region of the spectrum and is taken as the mean ray between the C and F lines Indices of the crown glass for the C D F lines are pc 1 514 HD 1 517 pF 1 523 indices of the flint glass for C D F lines are u c 1 644 U D 1 650 F 1 664 2 25 3 flint glass crown glass

Q1 In an eye piece field lens and eye lens have focal lengths 7 5cm and 7 3 cm To eliminate spherical aberration distance between them would be O 0 2cm O 0 4cm O 0 1cm 4 1 00 13 O 0 5cm

Q2 Osin 3 4 Otan 4 1 Light travels in two media A and B with speeds 1 8 x 10 ms and 2 4 x 10 ms respectively Then the critical angle between them is 00 26 O

15 A plano convex lens fits exactly into a plano concave lens Their plane surface are parallel to each other If lenses are made of different materials of refractive index and and R is radius of curvature of the curved surface of the lenses then focal length of the combination is R 1 2 H H 3 1 2R anal ev R 2 H H 4 7 R 9

Monochromatic light rays parallel to x axis strike a convex lens AB If the lens oscillates such that AB tilts upto a small angle 0 in radian on either side of y axis then find the distance between extreme positions of oscillating image f focal length of the lens A 2 sec0 1 C sec8 1 B f sec 0 D the image will not move 18 A B

A system of two glass system as shown in the figure of radius of curvature 50 cm each and respective refractive indices and nous The focal length of the system is 1 25 cm 101 3 2 43 3 2 2 100 cm tim

5 Question No 75 50 Multiple Choice Select 1 out of 4 options for the question below Light is falling on surface S1 S2 S3 as shown in figure 55 60 4 65 69 70 74 75 Options OO Surface S Surface S Surface S Max Mark s 1 5 S only S and S2 only

1 17 22 23 24 25 41 27 28 18 19 20 32 33 34 35 36 37 38 39 40 51 28 29 30 42 43 44 45 46 47 48 49 61 66 56 57 71 52 53 54 55 49 50 57 58 59 60 62 63 64 65 67 68 69 70 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 Options O JWS the bending of light from denser D medium into a rarer R medium R D R R D D

A glass sphere 4 of radius 12 cm has a small mark at a distance of 3 cm from its centre Where this mark will appear when it is viewed from the side nearest to the mark along the line joining the centre and the mark 1 8 cm inside the sphere 2 12 cm inside the sphere 3 4 cm inside the sphere 4 3 cm inside the sphere

Question No 33 Max Mark s 02 Multiple Choice Select 1 out of 4 options for the question below When a ray of light goes from higher refractive index to lower refractive index which of the following is correct Options the ray of light will bend towards the normal the ray of light will bend away from the normal the ray of light will go un deviated None of these

A plano covex lens when silvered on the plane side behaves like a concave mirror of focal length 60 cm However when silvered on the convex side it behaves like a concave mirror of focal length 20 cm Then the refractive index of the lens is A 3 0 C 1 0 B 1 5 D 2 0

Jum 1 2000 2 4000 neet prep sin 7 2 sin 1 sin 3 sin 4 sin 2 A cylindrical solid rod made up of material of refractive index is given A light beam enters from one circular end of the cylinder and comes out just brushing the outer surface along the length What should be the angle of incidence on the circular face f High Yielding Test Series Part Test 7 Page 1 Contact Number 9667591930 8527521718 3 60 cm 4 20 cm 163 When a concave mirror of focal length f is immersed in water its focal length becomes f then

A beam of light is emitted 8 4 cm beneath the surface of a liquid and strikes the air surface 7 2 cm from the point directly above the source Part A If total internal reflection occurs what can you say about the minimum possible index of refraction of the liquid Express your answer using two significant figures VA O

11 Figures a and b show refraction of a ray in air incident at 60 with the normal to a glass air and water air interface respectively Predict the angle of refraction in glass when the angle of incidence in water is 45 with the normal to a water glass interface figure c Glass 359 Air 60 Glass

142 A fish is a little away below the surface of a lake If the critical angle is 49 then the fish could see things above the water surface within an angular range of 6 where 1 0 49 2 0 90 3 098 4 0 24

GEOMETRICAL OPTICS OBJECTIVE PHYSICS A ray of light strikes a plane mirror at an angle of incidence 450 as shown in the figure After through which the mirror should be rotated if the total deviation of the ray is to be 90 is a 10 clockwise b 10 anticlockwise c 20 clockwise d 20 anticlocwise 90

Plane polarised light is passed through a 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 Question Type Single Correct Type 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 The intensity of light is twice maximum

A small object is stuck on the surface of a glas sphere u 1 5 of radius 20 cm It is viewed from the diametrically opposite position The position c image from centre will be 1 40 cm 3 20 cm 2 60 cm 4 80 cm

Select one O both near and far points get farther O the near point gets closer while the far point gets farther O the far point gets farther while the near point doesn t change both near and far points get closer O the near point gets farther while the far point gets closer the near point gets farther while the far point doesn t change

0 A ray incidents on medium as shown All interfaces are parallel and the total deviation 8 suffered by ray for corresponding angle of incidence 0 Choose CORRECT option options A 0 30 815 1 2 H B 0 46 8 88 C 0 0 8 0 D 0 80 8 20

When you look at a fish in a still stream from the bank the fish appears shallower than it really is due to refraction From directly above it appears Select one O it depends on your height above the water O deeper than it really is O shallower than its real depth at its actual depth

1 5 By drawing a 5 3 pts The diagram below shows a solid glass sphere with refractive index n neat and labeled diagram describe what happens to the incident ray as it passes through the solid ob until it emerges on the other side Please draw the additional lines surface normal would have weak reflection at each interface solid glass sphere n 1 5 X Incident ray

A SI mall piece of wire bent into on L shape with upright and horizontal portions of equal lengths is placed with the horizontal portion along the axis of the concave mirror whose radius of curvature is 10 cm If the bend is 20 cm from the pole of the mirror then the ratio of the lengths of the images of the upright and horizontal portions of the wire is A 1 2 B 3 1 C 1 3 D 2 1