Geometrical Optics Questions and Answers

When a bright source is placed 30 cm in front of a lens there is an erect image 7 5 cm from the lens There is also of faint inverted image 6 cm in front of the lens due to reflection from the front surface of the lens When the lens is turned round this faint inverted image is seen 10 cm in front of the lens Refractive index of Find x the lens is 1 10

Images formed by an object placed between tw plane mirrors whose reflecting surfaces make a angle of 90 with one another lie on a 1 Straight line 2 Parabola 3 Circle 4 Ellipse 10005 Ph 011 476234

greater than critical angle 44 Due ot a vertical temperature gradient in the atmosphere the index of refraction varies Suppose index of refraction varies 11 0 as n no 1 ay where n is the index of refraction at the surface and a 2 0 10 m A person of height h 2 0m stands on a level surface Beyond what distance he will not see the runway y 00 h 2m X

Light is incident at an angle a on one planar end of a transparent cylindrical rod of refractive index 1 Determine the least value of n so that the light enter ing the rod does not emerge from the curved surface of the rod irrespective of the value of a o at n

150 The ex of a lens material is and focal length f Due to some chemical changes in the material its refractive index has increased by 2 The percentage decrease in focal length for u 1 5 will be 10 2 20 3 6 4 8

Focal length of objective of a compound microscope is 4mm and image is formed at a distance of 224 mm from it If angular magnification is 550 then focal length of eye piece for normal adjustment is 2 5 cm 2 3 cm Mod 3 5 cm Object 50m 4 10 cm 90cm 8 10

A cubical vessel has opaque walls An observer dark circle in figure below is located such that she can see only the wall CD but not the bottom Nearly to what height should water be poured so that she car see an object placed at the bottom at a distance of 10 cm from the corner c Refractive index of water 1 33 a 10 cm b 16 cm c 27 cm d 45 cm A B ID C

4 An equiconvex lens of glass of refractive index 1 5 is immersed in a liquid of refractive index 1 6 If the radius of curvature of each surface is 0 1 m find the nature and focal length of the lens

For a normal eye the cornea of eye provides a converging power of 40 D and the least converging power of the eye lens behind the cornea is 20 D Using this information the distance between the retina and the cornea eye lens can be estimated to be NEET 2013 1 109 60 1 2 1 3 147 1 2 5 cm 21 67 cm 3 1 5 cm 4 5 cm Pictop P 20 GOD 2

PTICAL INSTRUEMENT 02 A vessel is half filled with a liquid of refractive index u The other half of the vessel is filled with an immiscible liquid of refractive index 1 5u The apparent depth of vessel is 50 of the actual depth The value of u is 1 1 6 2 1 67 3 400 12 For the cond 3 1 5 4 1 4 A clear transparent glass sphere u 1 5 of radius R is immersed in a liquid of refractive index 1 25 A parallel beam of light incident on it will converge to a point The distance of this point from the centre will be 1 3R 2 3R 3 R 4 R mini

A fish looking up through the water sees the outside world contained in a circular horizon 4 If the refractive index of water is and the 3 fish is 12 cm below the surface the radius of this circle in cm is 2005 2 36 73 4 5 36 D Ti 4 36 5

is fixed to the ceiling Abulb is to 20 cm be placed on the axis of the mirror A circular area of radius R 1 m on the floor be illuminated after reflection of light from the mirror The height of the room is 3m What should be the maximum distance 23 A stom from the centre of the mirror where bulb is be placed so that the required area is iluminated is in cm to B B 3 x 1 24 A CO t

In a compound microscope the focal length of objective lens is 1 2cm and focal length of eyepiece is 3 0cm When the object is kept at 1 25cm in front of objective the final image is formed at infinity Magnifying power of compound microscope should be nearest to Use D 25cm 1 200 3 400 2 100 4 150 ints of two convex

56 A ray of light refracts from medium 1 into a thin layer of medium 2 crosses the layer and is incident at the critical angle on the interface between the medium 2 and 3 shown in the figure If the angle of incidence of ray is 0 the value of is bla 1 sin 1 1 2 3 8 610 0 1 6 H 1 8 3 1 3 2 sin 13 18

An object is placed at a distance of 15cm from a convex lens of focal length 10cm Find the distance at which a convex mirror of focal length 10cm should be placed on the other side from the lens so that final image coincide with the object itself 1 20cm 3 15cm 2 10cm 4 30cm

2 A biconvex lens has a radius of curvature of magnitude 20 cm Which one of the following Options deseribe best the image formed of an object of height 2 cm placed 30 cm from the lens 1 Virtual upright height 2 Virtual upright height 0 5cm 3 Real inverted height 4cm 4 Real inverted height 1cm 1cm

Mirror in the arrangement shown in figure is moving up with speed 4 cm sec Find the speed of final ima 16JP12 object O in cm s formed after two refraction and one reflection O water 4 3

The principal section of a glass prism is an isosceles triangle ABC with AB AC The face AC is silvered A ray of light is incident normally on the face AB and after two reflections it emerges from the base BC perpendicular to the base Angle BAC of the prism is b 36 c 60 a 30 EAMCET 2004 d 72

2 A concave mirror of focal length f produces a real image times the size of the object The distance of the object from the mirror is

As shown in figure a liquid of refractive index n is poured onto the concave surface of concavo convex lens R and R are the radii of curvature of convex and concave surfaces of the lens respectively and R 2R The refractive index of material of lens is n For which combination of n and n the whole system behaves as a diverging lens R n 1 n 1 2 and n 1 8 2 n 1 63 and n 1 35 3 n 1 56 and n 1 33 1 R

A beam of light from a source L is incident normally on a plane mirror fixed at a certain distance x from the source The beam is reflected back as a spot on a scale placed just above the source I When the mirror is rotated through a small angle 0 the spot of the light is found to move through a distance y on the scale The angle 0 is given by 2017 a c y X X y b d X 2y y 2x u

A light ray is incident on a rotating mirror which is rotating with angular speed 3 rad s as shown in figure The speed of bright spot on the wall when 0 30 0 Incident ray Wall 1

13 1 u of mass 931 5 MeV of energy HD Question 25 O 65 55 75 0 35 90 Mirror A You have a children s toy part of which is formed of two small plane mirrors attached at right angle to each other You send a laser beam at angle of incidence 35 with one of the mirrors What is the angle the final beam will reflected as it leaves the mirrors after being reflected by the second mirror Mirror B nuclei not decayed Half life T1 2 0 693 A decay constant 1 p

Alens has one concave surface of R 2 m an convex surface with R 3 m then focal length lens is If u 1 5 1 12 m 3 24 m 2 12 m 4 6 m

A light ray traveling through the air strikes a uniformly thick piece of plexiglass n 1 51 at an angle of 45 0 to the normal and then exits on the other side of the plexiglass onto water n 1 33 Determine the angle of refraction through the water 50 Points Hint You ll need to apply Snell s law more than once

A convergent lens forms a real image 0 78 times the size of the object The object dis tance is 184 cm P h Scale 10 cm Find the distance of the focal point from the center of the lens Answer in units of cm Answer in units of cm i

Coherent light of frequency 6 32x10 Hz passes through two thin slits and falls on a screen 81 0 cm away You observe that the third bright fringe occurs at 3 16 cm on either side of the central bright fringe For related problem solving tips and strategies you may want to view a Video Tutor Solution of Determining wavelength How far apart are the two slits Express your answer in millimeters d H VOAE Submit Part B Request Answer A At what distance from the central bright fringe will the third dark fringe occur Express your answer in centimeters I m

What are three behaviors of light that cause it to be thought of as a wave

A convergent lens forms a real image 1 36 times the size of the object The object dis tance is 17 9 cm h 9 Scale 10 cm H Find the distance of the focal point from the center of the lens Answer in units of cm Answer in units of cm Your res 1 2 3 4 5

from flint glass to water If the incident angle is 22 find light with a wavelegth of 700x10 m and a speed a speed after refraction b wavelength after refraction c angle of refraction Unit 10 4 Optics

5 Make a ray diagram to locate the image of the paramecium or hairy ear The mutant paramecium is 1 0 cm tall and placed 3 0 cm from a lens that has a focal length of 5 0 cm Find the image height

Light traveling through air strikes the boundary of some transparent material The incident light is at angle of 14 degrees relative to the normal The angle of refraction is 25 degrees relative to the norm nair is about 1 00 a 5 points Draw a clear physics diagram showing each part of the problem b 5 points What is the angle of reflection c 5 points What is the index of refraction of the transparent material d 5 points What is the critical angle for this material and air e 5 points What is Brewster s angle for this material and air

1 Monochromatic light passes between 2 media If the angle in medium 1 is 45 and the angle in medium 2 is 30 calculate the ratio of light speeds between media 1 and 2 2 The speed of light in a medium is 2 4x 10 m s What is the absolute index of refraction of the medium 3 A light ray f 5 09 x 10 Hz is refracted as it travels from water into flint glass The angle of refraction is 37 What is the angle of incidence

A divergent lens forms a virtual image 0 73 times the size of the object The distance between object and image is 15 cm f h Pq h Scale 10 cm H Find the distance of the focal point from the center of the lens Answer in units of cm

A divergent lens forms a virtual image 0 68 times the size of the object The object dis tance is 11 5 cm h P 9 h Scale 10 cm Find the distance of the focal point from the center of the lens Answer in units of cm

object is 30 cm in front of a converging of focal length 10 cm The image is 01 real and smaller than the object O2 real and larger than the object 3 real and the same size than the object 4 virtual and the same size than the object HE

A convergent lens has a focal length of 9 4 cm The object distance is 20 4 cm P h f Scale 10 cm Find the distance of the image from the center of the lens Answer in units of cm Answer in units of cm part 2 of 2 9 Find the magnification

004 part 1 of 2 10 0 points A convergent lens has a focal length of 9 4 cm The object distance is 20 4 cm SEFFEFFFFFFFFE Scale 10 cm Find the distance of the image from the center of the lens Answer in units of cm 005 part 2 of 2 10 0 points Find the magnification 9

A light beam in air enters a transparent material at an angle of 38 00 degrees with respect to the normal After refraction it makes an angle of 14 76 degrees with respect to the normal Air has an n of 1 000 What is this transparent material USE SNELL S law vimppo material carbon dioxide water ethyl alcohol glycerine ice crown glass acrylic polymethylmethacrylate diamond index of refraction n 1 0005 1 333 1 362 1 473 1 31 1 50 1 62 1 46 2 417 3p

Consider the lens shown at the right An object is placed at a position beyond the 2F position left of 2F 2F F Select one O a between the focal point F and the lens O b beyond the 2F point O c at the 2F point O d between the focal point F and the 2F point TERFERE F 2F The image will be located

O they are virtual because they are projected onto a screen Othey are real because they are reflected off of a mirror

An object is placed 10 9 cm in front of a convex lens A virtual image is produced at 46 8 cm behind the lens What is the focal length of the lens 1 2 1 2 1 Round your answer to the nearest 0 1 one decimal place Do not add units

water n 1 33 O sapphire n 1 77 glass n 1 52

What happens when an object is place exactly at the focal length of a convex lens Choose all that apply O no image is produced an image appears on top of the object O a real image is produced O a virtual image is produced

If the angle of incidence is 74 what is the angle of reflection Do not add units to your answer

An object is placed 3 6 cm in front of a convex lens with a focal length of 4 5 cm Which of the following best describes the image produced O A virtual upright image is produced at 2 0 cm O A real inverted image is produced at 18 cm O A virtual upright image is produced at 18 cm O A real inverted image is produced at 2 0 cm

Problem 8 An object is 30 cm in front of a concave spherical mirror that has a focal length of 10 cm a What are the image distance q and magnification M Is the image virtual or real Is the image inverted or upright b Repeat the same calculation for image distance q magnification M for a convex mirror Is the image virtual or real Is the image inverted or upright

Light is not refracted when it is Select one O a traveling from air into a glass of water at an angle of 35 to the norma O b traveling from air into a diamond at an angle of 45 O c striking a wood surface at an angle of 75 O d traveling from water into air at an angle of 35 to the normal

All of the following images can be formed by a converging lens except which one Select one O a real upright and magnified O b real inverted diminished O c virtual upright and magnified O d real inverted and magnified

The diagram below shows an incident ray approaching a lens Upon striking the lens this ray will Select one 2F F a refract and pass through point F b refract and pass through point 2 F C refract and pass through in a line with point F on the left side Od refract and pass through in a line with point 2 F on the left side F 2F