Geometrical Optics Questions and Answers

e of el 20 Critical angle for light going from medium i to ii is 8 The speed of light in medium i is v then the speed of light in medium ii is a v 1 cose b d c cose V sin 0 1 sin 8 adium of

3 34 The radi of curvature of the surfaces of a double convex lens are 20 cm and 40 cm respectively and its focal length is 20 cm What is the refractive inder of the material of the lens 512 b c 3 35 A convex lens is dipped in a liquid 5 3 d 5

An object is placed at 20 cm from a convex mirror of focal length 10 cm The image formed by the mirror is Question Type Single Correct Type 1 2 3 4 Real and 10 cm from the mirror Virtual and at 10 cm from the mirror 20 Virtual and at 3 cm from the mirror 20 Real and at 3 cm from the mirror

c 90 d 40 12 The apparent depth of a needle lying at the bottom of the tank which is filled with water of refractive index 1 33 to a height of 12 5 cm is measured by a microscope to be 9 4 cm If water is replaced by a liquid of refractive index 1 63 upto the same height 17 For a tot What distance would the microscope have to be moved to focus on the needle again a 1 73 cm b 2 13 cm is correct a Lig d 2 9 cm b Lig c 1 5 cm c Lig d Lig refract a 50 b 60 A point luminous object O is h from front face Observer microsc again a 1 C c 0 5 19 TC

A light ray passes through the focus point of a convex lens and is then incident on the lens Which of the following figure depicts the correct path of light beam f f f f F F F A B C D a Fig A b Fig B c Fig C d Fig D

A rod of glass u 1 5 and of square cross section is bent into the shape shown in the figure A parallel beam of light falls on the plane flat surface A as shown in the figure If d is the width of a side and R is the radius of circular arc then for what maximum value of light entering the d R glass slab through surface A emerges from the glass through B A B 1 1 5 2 0 5 3 1 3 4 None of these

a A converging lens of focal length of 12 cm and diverging mirror of focal length 7 5 cm are placed 5 cm apart If the final image is formed by the combination coincides with object itself then position in cm of the point object from the lens is

A thin equiconvex glass lens of refractive index 1 5 has a power of 5D When the lens is immersed in a liquid of refractive index it acts as a divergent lens of focal length 100 cm The value of of liquid is 1 4 3 2 3 4 3 5 3 4 8 3

In the displacement method a convex lens is placed in between an object and a screen If the magnifications in the two positions are m and m2 and the displacement of the lens between the two positions is x then the focal length of the lens is X 1 m m2 2 3 4 X m1 m2 X m m X m m

Two illuminated point objects O and 02 are placed at a distance 24 cm from each other along the principal axis of a thin convex lens of focal length 9 cm such that images of both the objects are formed at the same position Then the respective distances of the lens from O 1 and O in cm are O O O 12 and 12 18 and 6 14 and 10 16 and 8

A point like light source is placed to the symmetry axis of a hemisphere shaped piece of glass of radius 20 cm 10 cm away from the plane surface The refractive index of glass is 1 5 A ray of light whose angle of incidence is 60 is incident as show in the diagram After coming out of amisphere ray of light will again cut the symmetry axis at some point Find out distance between source and that point 60 10 cm 20 cm

A plane mirror is placed at the bottom of a fish tank filled with water of refractive index The fish is at a height 10 cm above the plane mirror An observer O is vertically above the fish outside water The apparent distance between fish and its image is 10 cm O observer mirror 4

A converging lens of focal length 30 cm and diverging lens of focal length 20 cm are kept 15 cm apart with their principal axes coinciding Where shall an object be placed to form an image at infinity

A hemisphere of radius R and refractive index 2 is placed in a liquid of refractive index 3 as shown in figure A ray is incident at point P at an angle 60 As the ray emerges out from the hemisphere the angle of refraction is 0 The distance of the point P from A is A 2R B 3R 60 P 2R C 2 3 3 D 2R

a concave lens of focal length f the relation between object and image distances u and v respectively from its pole can best be represented by u v is the reference line Mothengt nathon A B f V f u v u v u mothang T son matho hon

A luminous point object is moving along the principal axis of a concave mirror of focal length 12 cm towards it When its distance from the mirror is 20 cm its velocity is 4 cm s The velocity of the Image in cm s at that instant is 6 towards the mirror 6 away from the mirror 9 away from the mirror 9 towards the mirror

A ray of light is incident normally on face AB of a prism of refractive index 3 2 The largest value of angle 0 so that ray is totally reflected from face AC when prism immersed in oil of refractive index 5 4 is given by A oil B 3 2 O sin 3 3 5 4 O sin 1 5 cos 6 oil 0 C

A ray of light strikes a plane water air interface from within the water at an angle of incidence i Which one of the following statements is correct a If i is 90 the angle of refraction will be the critical angle b If i is equal to the critical angle the reflected and refracted rays will be at right angles to each other c If i is less than the critical angle all the light is refracted and the angle of refraction is greater than i d If i is less than the critical angle some light is

A convex lens forms a real image on screen placed at distance of 60 cm from the object When lens is shifted towards screen by 20 cm another image of object is formed on screen The focal length of the lens is 12 cm 40 2cm 24 cm 30 cm

An object is placed in front of a convex mirror of radius of curvature 20 cm Its image is formed 8 cm behind the mirror The object distance is O 40 cm O 20 cm O 60 cm 30 cm

Figure shows a ray of light passing through a prism If the refracted ray QR is parallel to the base BC show that i r r A 2 ii angle of minimum deviation Dm 2i A P A Agho Ve R S

A man cannot see clearly the objects beyond a distance of 20 cm from his eyes To see distant objects clearly he must use which kind of lenses and of what focal length 1 10 cm convex 3 20 cm convex 2 100 cm concave 4 20 cm concave

of light strikes a piece of transparent glass having cross section as shown in the figure below Correct shape of the emergent wavefront will be figures are schematic and not drawn to scale Glass Light a Air Air b c dic d

The objective and eye piece of an astronomical telescope are double convex lenses with refractive index 1 5 when the telescope is adjexted to infinity the separation between the lenses is 16cm I the space between the lenses is now filled with water and again telescope is adjusted for infinity Then the present separation between the lenses is in centimeter

View in English One face of a rectangular glass plate 6 cm thick is silvered An object held 8 cm in front of the first face forms an image 12 cm behind the silvered face The refractive index of the glass is 1 correct Answer 3 Our Answer 4 tatus incorrect 04 0 8 16 Add to Bookmark List One face of a rectangular gloss plate 6 cm thick is silvered An object hal 4

If magnitude of dispersive power of two lens are 0 024 and 0 036 then focal length be for aberration free combination Question Type Single Correct Type 1 30 cm 40 cm 2 30 cm 45 cm 3 10 cm 30 cm 4 20 cm 35 cm

0 14 Hz d More information is required A lens held above a coin placed on a table forms an image of the coin After the lens is moved vertically a distance equal to its focal length it forms another image of the coin equal in size to the previous image I diameter of the coin is 2 0 cm what is the diameter of the image a 3 0 cm c 5 0 cm 1 b 4 0 cm d 6 0 cm

40 cm What is the distance of the final image formed by this lens system 1 120 cm to the right of lens A 2 90 cm to the right of lens A 3 22 5 cm to the right of lens B 4 45 cm to the right of lens B 8 A person can see clearly objects only when they lie between 50 cm and 400 cm from his eyes In order to increase the maximum distance of distinct vision to infinity the type and power of the correcting lens the person has to use will be 1 convex 2 25 diopter 2 concave 0 25 diopter 3 concave 0 2 diopter 4 convex 0 5 diopter 3 54 0 cm 4 37 3 cm 30 cm 10 A concave mirror of the focal length fi is placed at a distance of d from a convex lens of focal length f2 A beam of light coming from infinity and falling on this convex lens concave mirror combination returns to infinity The distance d must be equal 1 f f 7 616 4 2f1 f 9 An astronomical telescope has an objective and eyepiece of 13 focal lengths 40 cm and 4 cm respectively To view an objectThe refracting angle of a prism is A and refractive index of 200 cm away from the objective the lenses must bethe material of the prism is cot A 2 The angle of minimum separated by a distance 1 46 0 cm 2 0 0 cm deviation is 1 180 3A 2 180 2A 3 90 A 4 180 2A 11 You are standing on the shore of a lake You spot a fish swimming below the lake surface You want to kill the fish first by throwing a spear and next by pointing a high power laser torch How should you aim the spear and torch respectively from the options given below I above the apparent position of the fish II below the apparent position of the fish III directly at the apparent position of the fish 1 SPEAR II LASER III 2 SPEAR I LASER II 3 SPEAR II LASER II 4 SPEAR III LASER III 12 A boy is trying to start a fire by focusing sunlight on a piece of paper using an equiconvex lens of focal length 10 cm The diameter of the sun is 1 39 x10 m and its mean distance from the earth is 1 5 x 10 m What is the diameter of the sun s image on the paper 1 9 2 x 104 m 2 6 5 x 10 m 3 6 5 x 10 m 4 12 4 x 10 m 14 In an astronomical telescope in normal adjustment a straight line of length L is drawn on inside part of the objective lens The eye piece forms a real image of this line The length of this image is 1 The magnification of the telescope is 1 4 1

Which statement best describes the refraction of light When light enters a new medium at an angle it travels in a straight line through the medium without changing direction When light strikes the boundary between two mediums the light ray bounces off at an equal angle to the incidence angle When light enters a new medium its path becomes unpredictable When light enters a new medium it changes direction bends in a predictable manner

colors A ray of light is incident at an angle of incidence i on one face of a prism of angle A assumed to be small and emerges normally from the opposite face If the refractive index of the prism is the angle of incidence neet prep 40 cm 30 cm Two convex lens A and B each of focal length 30 cm are separated by 30 cm as shown in the figure An object O is placed at a distance of 40 cm to the left of lens A Ray Optics NEET 2020 What is the distance of the final image formed by this lens system 1 120 cm to the right of lens A 2 90 cm to the right of lens A 3 22 5 cm to the right of lens B 4 45 cm to the right of lens R Contact Number 9667591930 8527521718 3 2f1 f2 4 2f1 f2 11 You are standing on the shore of a lake You spot a fish swimming below the lake surface You want to kill the fish first by throwing a spear and next by pointing a high power laser torch How should you aim the spear and torch respectively from the options given below I above the apparent position of the fish II below the apparent position of the fish III directly at the apparent position of the fish 1 SPEAR II LASER III 2 SPEAR I GRADIL Page LASER II LACRn It

A cylindrical vessel whose diameter and height both are equal to 30 cm is placed on a horizontal surface and a small particle P is placed in it at a distance of 5 0 cm from the centre An eye is placed at a position such that the edge of the bottom is just visible see figure 18 E8 The particle P is in the plane of drawing Up to what minimum height should water be poured in the vessel to make the particle P visible 30

A convex lens of focal length f 20 cm is placed in front of a plane mirror as shown in the figure 20 cm An object O is placed in front of convex lens For what value of x final image will coincides with the object x 20 cm b X 40 cm 30 cm

A cylindrical beam of light having a variable intensity 1 is incident on the curved surface of a fixed cone of base radius R Intensity of beam lor Conical surface is completely reflecting surface If the force exerted by R where lo is constant in simplest ratio Where k and k are integers and C is the speed of Changes with radial distance r according to the function 1 K loR sin 0 he light on the cone is of the form k C ight Then the value of k k will be 1 R3 58 rigid rod fixed conical surface

An object is placed in front of a convex mirror at a distance of 50 cm A plane mirror is introduced covering lower half of the mirror If the distance between the object and the plane mirror is 30 cm it is found that there is no parallax between the images formed by two mirrors Then radius of curvature of convex mirror 1 30 cm 3 25 cm 2 40 cm 4 15 cm

Q 37 O When a point source of light is placed at a depth h inside a liquid of refractive index then the light rays come out of the surface of the liquid through a circular area only The radius of the circular area depends on Depth h R I of the liquid Colour of the light 4 All of these 00 40

Two mirrors mounted vertically are made to move towards each other with a speed v m s each A particle that can bounce back between the two mirrors starts from one mirror when the mirrors are d meters apart On reaching the second mirror it bounces back and so on If the particle keeps on travelling at a constant speed of 4v m s how many trips can it make before the mirrors run into each other and what total distance does it cover 1 5 1 d 2 2 0 d 3 0 6 1 d 016 d

Two plane mirrors M M2 have their reflecting faces inclined at 0 Mirror M receives a ray AB reflects it at B and sends it as BC It is now reflected by mirror M along CD as shown in the figure Total angular deviation suffered by the incident ray AB is 0 B Z TTTTI O 890 20 C 82 D M2 A

An object moves towards a concave lens with speed 5 mm s of focal length 20 cm Then what is image speed when object is at 30 cm from lens A 0 4 mm s B 0 2 mm s C 0 16 mm s D 0 8 mm s

8 In a demonstration of dispersion without deviation phenomenon of thin prism combination a prism X is chosen with refracting angle 5 and refractive index 1 40 It is combined with another prism Y of material refractive index 1 50 The refracting angle of prism Y is 1 3 2 4 3 6 25 4 6

A converging lens forms an image of an object on a screen The image is real and has twice the size of the object If the positions of the object and the screen are interchanged leaving the lens in its original position what would be the size of the new image A twice the size of the object B same size as that of the object C half the size of the object the imag will not form on the anoon

1 325 K 2 375 K 3 300 K 4 350 K Focal length of a magnifying glass is 12 5 cm Ratio 20 of maximum and minimum magnifying power is 1 2 3 2 1 3 3 3 1 4 3 2 Which of the following not a electrostatics field 21 2

A 8 B 5 C 10 D 12 O A square plate of sides 3 cm is placed at 20 cm from concave mirror The focal lengt of concave mirror is 15 cm Then the area of image formed by concave mirror wil be cm A 124 B 81 C 144 D 169

A lens with a focal length of 18 cm is used to project an image onto a screen If the original object is 22 cm away from the lens how many cm from the lens will the image be Your Answer

One night a person of height h 1 8m is standing on the bank of a straight canal On the opposite bank a lamp is installed at height H 5 4m on a lamp post Light from the lamp appears as a bright spot after starts walking along the bank the spot appears to him moving at constant speed up relative to ground Speed of the person is then n n is A 2 C 12

A thin lens of focal length f is used as a magnifying glass Which of the following statements is true respectively about the type of lens and the distance d of the object from the lens A converging d 2f B diverging f d 2f C converging d f D diverging d 2 f

A convex lens made of 5 different transparent materia is used to make an image of an object placed in front it The number of images formed will be H45 1 2 2 3 3 4 4 5 15

A 9 CM tall object placed 18 cm in front of a convex mirror of focal length fif the image formed is 3 times smaller than the object find out the focal length of the mirror state the nature size and position of the image formed

neet prep 29th Octob Cont 1 A spherical fishbowl of radius 15 cm is filled with water of refractive index A cat standing outside in air at a distance of 30 cm from the centra of fishbowl is looking at the fish At what distance from the centre would the cat appear to fish situated at the centre 6 1 45 cm 2 30 cm 3 15 cm 2 3 4 The cm the

An object is approaching a thin convex lens of focal length f with speed vo The magnitude of the rate of change of lateral magnification of image w r t time when the object is at a distance from the lens is f fvo Vo 3V0 f 3

in n 12 Assertion The nature of the image of an object depends on the size of the mirror Reason It is not possible to obtain a real image by a plane mirror 1 Both Assertion and Reason are true and the reason is the correct explanation of the assertion 2 Both Assertion and Reason are true but the reason is not the correct explanation of the assertion 3 Assertion is a true statement but Reason is false 4 Both Assertion and Reason are false statements 13