Geometrical Optics Questions and Answers

An object is placed at a distance of 15 cm from a convex lens of focal length 10 cm On the other side of the lens a convex mirror is placed at its focus such that the image by the combination coincides with the object itself What is the focal length in cm of the convex mirror Of O 0

Q 133 The ratio of wavelengths of the last line of Q 133 Balmer series and the last line of Lyman series is 1 1 2 4 3 0 5 4 2 3 1 1

A coherent parallel beam of microwaves of Young s double slit apparatus The separation between the slits is 1 0mm The intensity of microwaves is measured on screen placed parallel to the plane of the slits at a distance of 1 0m from it as shown in the figure YA D 1 0m Screen If the incident beam falls normally on the double slit apparatus the y coordinat of all the interference minima on the screen will be 1 3 1 3 BY 5 15 7 A 3 D 5 1 C 7 6 If the incident beam makes an angle of 30 with the x axis as in the dotted arro shown in the figure the y coordinates of the first minima on either side of the central maximum will be C 1 3 15 7 Td 1 0mm 3 15 7 3 2 15 7 B D 3 15 7

A ray of light passes from a denser to a rarer medium At the surface of separation the angle of incidence is i and the angle between reflected and refracted rays is 90 If the angle of reflection and refraction are r and r respectively then the value of critical angle is A sin tanr B sin tanr C sin tani D tan sini of two media X and Y

9 In equilateral triangle prism under minimum deviation ray inside prism is a Perpendicular to base b Parallel to base c Neither parallel nor perpendicular to base d may be parallel to base

If a torch is submerged in water and sends light along path as shown in the figure along OA making an angle of incidence of 30 Then the angle of refra ction in air 1 is a Greater than 30 but less than 90 b Less than 30 c Equal to 30 d Equal to 90 Torch Water

A ray of light is incident on a mirror and the light travels in the direction x 3y and after reflection travel in the direction x What is the angle of incidence with respect to the normal to the mirror a 30 degrees b 60 degrees 90 degrees 120 degrees

4 The length of the tube of a compound microscope is 15 cm The focal length of objective and eye lenses are 1 cm and 5 cm respectively The magnifying power of microscope for relaxed vision is 1 50 2 75 3 25 4 100

332 5 23 AB is a man of height 2m and Mis a mirror of length and mass 0 1 kg Initially top of mirror Mand A are at the same level and the Mstarts falling freely always remaining vertical If the level of the eyes of the man is 1 5 cm below his head A find the time after which the man sees the reflection of his feet M A

have 60 Two slabs P Q of transparent mate thickness in ratio 2 5 If a ray of light take same time to move from A to B and B to C then refractive index of Q w r t P will be P Q 12 1 0 4 3 1 4 A B C 2 2 5 4 1 85

10 If the plane surface of a planoconvex silvered then it will behave as 1 Converging mirror 2 Diverging mirror 3 Plane mirror 4 May behave as 1 or 2 ed by 2133766 aesl id Standard XI Stream NEET Jul 14 2021 at 5 17 PM d your responses Type Text pe your answer here OR you can upload an tachment from the option below

70 A convex lens forms the image of the point object O on the screen If a glass slab of thickness 3 cm and refractive index 1 5 is put as shown below then to have the image of the object on the screen the object should be shifted O 42 KI 3 cm 1 Away from the lens by 1 cm 2 Away from the lens by 1 5 cm 3 Towards the lens by 1 cm 4 Towards the lens by 1 5 cm screen

3 50 m s 144 Light ray is incident at an angle of 60 on one face of a rectangular prism of refractive angle 90 If light ray grazes the second face then the refractive index of material of prism is 3 1 3 5 2 2 2 7 2 4

A parallel beam of light is incident on a combination of two optical systems S S with their principal axis coinciding as shown The final beam after all optical processes is also parall principal axis 300 S S If final beam diameter is more than incident one then S S can be both convex lens If final beam diameter is more than incident one then S and S can be convex lens and concave mirror respectively If final beam diameter is equal to that of incident one then S S can be concave lens and convex lens respectively If final beam diameter is less than incident one then S S can be convex lens and concave lens respectively

A transparent cube of 15 cm edge contains a small air bubble Its apparent depth when viewed througth one face is 6 cm and when viewed through the opposite face is 4 cm Then the refractive index of the material of the cube is O O C 2 0 2 5 1 6 1 5

36 A ray of light incident on an angle of incidence i The deviation produced E prism will be maximum when angle i take Mglass 2 1 30 3 60 2 45 4 90

All of the following statements are correct except O The magnification produced by a convex mirror is always less than one O A virtual erect same sized image can be obtained using a plane mirror O A virtual erect magnified image can be formed using a concave mirror O A real inverted same sized image can be formed using a convex mirror

13 Angle of a distant object formed at the objective of a telescope is 2 If focal length of objective and eyepiece of telescope is 200 cm and 20 cm then the size of image formed by the objective is approximately 1 20 cm 3 0 4 cm 2 9 12 cm 4 12 cm

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 g where Air Water O O O 0 49 0 90 8 98 0 24 1 2

Question An isosceles right angled glass prism is immersed in water The refractive indicesof 4 and 3 glass and water relative to air are and A 10 2 respectively If a ray of light is incident normally on the shorter face of deviation it will suffer the angle of deviation it will suffer the angle of the prism will be B 8 3 C 30 3

One of the refracting surface of a prism is silvered A ray is incident at an angle 60 such that it retraces its path The 3 angle of the prism is Only one correct answer A 30 B 45 C 60 D 75 i

In YDSE a transparent sheet of refractive index u 1 5 and thickness 1 5 m is introduced in the path of one of the waves then intensity at position of central maxima is 1 intensity in absence of sheet 5000 A 1 10 2 3 21 0 10 4 Zero

The magnification of an object placed in front of convex lens of focal length 20 cm is 2 To obtain a magnification of 2 the object has to be moved a distance equal to 1 10 cm 3 20 cm 2 30 m 4 40 cm

A narrow beam of light S is incident on a dihedral angle 60 formed by identical flat mirrors OM and ON secured on axis O Fig 1E 19 a After being reflected from the mirrors the light is focussed by lens L and gets into stationary receiver R The mirrors rotate with a constant angular velocity A y 0 M C PM N S B Fig 1E 19 a What part of the light energy of the beam will reach the receiver during a time that greatly exceeds the period of rotation if the beam passes at a distance a from an axis equal

A light ray is incident on a glass sphere of refractive index 3 at an angle of incidence 60 as shown in the figure The total deviation after two refractions will be 60 S 3 30 45 60 120

2 a In the Fresnel s biprism experiment a biprism of refractive index 1 73 and with apex angles of 0 85 and 0 75 is used to form interference fringes Find the fringe width for the light of wavelength 656 3 nm when the distance between the slit and the biprism is 25 cm and that between the biprism and screen is 75 cm

A diminished image of an object is to be obtained on a screen 1 0 m away from it This can be achieved by approximately placing A length B A convex mirror of suitable focal A concave mirror of suitable focal length D C than 0 25 m A convex lens of focal length less A concave lens of suitable focal length

Regular surface forms clear image while irregular surface forms blurry or no image We are irregular surfaces but people can see us clearly as an object If a mirror or an other object would be irregular and we would be standing in front of it then we could see a blurry image of ourselves but other people do not see us as blurry in the real life even tho we reflect irregular light rays

A point object O is kept in front of a plane mirror MM The line MOP makes an angle 60 with the mirror An observer is walking along the line APB perpendicular to MOP Find the length of his path along APB in which he can see the image of the object Given MO d MP 2d and length of the mirror L 2d M Fo M 0 P

A pencil is placed upright at a distance of 10 cm from a convex lens of focal length 15 cm The nature of the image of the pencil will be a b c d real inverted and magnified real erect and magnified virtual erect and reduced virtual erect and magnified

23 Light takes time t to X1 vacuum and the same light takes time to to travel a distance x in a medium The critical angle for that medium is 1 X t x t 3 sin t 1 sin 2 sin Xt x t1 4 sin X

I need a bird s eye view figure with the entire path of light and labels and explanation of h ow exactly the backscattering or deflection of light happens in the phenomenon of The Glory in the shadow side of the plane above the cloud Please explain in simple words as I m just 100

A point object O is placed at distance of 20 cm from a convex lens of focal length 10 cm as shown in figure At what distance x from the lens should a concave mirror of focal length 20 cm be placed so that final image coincides with the object 10 cm B 20 cm Final image can never coincide with the object in the given conditions A C D 40 cm 0 20cm X

9 The critical angle for refraction from medium 1 to air is and that from medium 2 to air is If medium 2 is denser than medium 1 Find the critical angle for refraction from medium 2 to medium 1 1 sin sin 0 2 sin 0 1 3 sin sin 0 2 sin sin 0 0 sin 0 1 sin sin A

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 O 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 O 5 m 5 m X

Please please please explain differentiate and tell the sig n of u and v in case of virtual object real object virtual ima ge real image in case of different types concave convex mi rrors and lens

An equi convex lens u 1 5 is combined with an equi concave lens u 1 3 The radii of curvature of all surfaces is the same Assume thin lenses A The combination behaves like a converging lens in medium of refractive index 1 4 and diverging lens in a medium of refractive index 1 6 B The combination behaves like a converging lens in a medium of refractive index 1 2 as well as 1 4 C The combination behaves like a diverging lens in medium of refractive index 1 2 as well as 1 6 D The combination behaves like a diverging lens in medium of refractive index 1 4 and converging lens in a medium of refractive index 1 6

6 A simple telescope consisting of an objective of focal length 60 cm and a single eye lens of focal length 5 cm is focussed on a distant object in such a way that parallel rays emerge from eye lens If the object subtends an angle of 2 at the objective the angular width of the image is Let tan 0 0 assuming 0 small 1 B 240 D 1 6 A 10 C 50

A concave lens of focal length 15 cm and a convex lens of focal length 30 cm are placed 15 cm apart with their principal axes coinciding A beam of light travelling parallel to the principal axis and having a beam diameter of 4 0 mm is incident on the combination In case l the light is incident from the side of the convex lens and in case II the light is incident from the side of the concave lens Then 15 cm yg xddd 30 cm a da s yg gut a au sac yw 3 z r WA MAUA chi yc ga Hulua uz ufaa sta i Fefa 1 JcII 37d 4 i c 7 3Tufaa da fa 11 cr da du cle 14 H GA G 15 cm 4 0 mm The diameter of the beam emergent from the combination is same in the two cases da faut dulua Ana gu B The diameter of the beam emergent from the combination in case l is 2 0 mm F 1 uga Ana ci 442 0 mm Correct Answer C The diameter of the beam emergent from the combination in case l is 8 0 mm F 1 Afa 44 8 0 mm The diameter of the beam emergent from the combination in case ll is 8 0 mm Mfa 11 uga Afa u 61 414 8 0 mm Correct Answer

A balloon is rising up along the axis of a stationary concave mirror of radius of curvature 20m A ball is dropped from the balloon at a height 15 m from the mirror when the balloon has velocity 2 m s Find speed of the image of the ball formed by concave mirror after 0 4 sec from the instant at which it was dropped in m s g 10 m s

Focal length of a glass lens 1 5 in air is 20 cm If it is dipped in water its focal length in water will be Only one correct answer Previous Next

One surface of an equiconvex lens of 1 5 and R 20 cm is silvered When an object is placed at distance x cm as shown a real image which is 2 5 times magnified is formed Find the value of x 1 5 R da 20 cm i gc HHTG i th udz s zudiga fchul uld 1 Ga ych azd ch cm uz zu Ga 2 da yc qzafag ufafa j 2 5 af a Z AMa ata A 0 Object axg 3 X Correct Answer 7

16 The reflected light wave and incident light differ from each other by a phase angle of when 17 1 Light enters into glass from air 2 Light enters into air from glass 3 Light enters into glass from diamond 4 Light enters into water from glass Converging rays are incident on a con

A prism placed in air made up of flint glass is such that any incident ray on one surface does not emerge from the second surface Critical angle for flint glass is 36 in air Then refracting angle A may be A 37 B 54 C 719 D 73

A 4 0 mm high object is placed on the axis of a lens It is placed at12 5 cm away from the lens with a focal length of 5 0 cm Determine the nature of the image real or virtual How high is the image Show work for credit

A telescope fo 140cm fe 5cm is used to view a distant tower 100 m high situated at a distance 3 km The tower is made of iron channels consisting rectangular grades of approximate size 2 x 2 m each in the image formed by telescope s objective each square channel will appear to be of area

A person 1 6 m tall is standing at the centre between two walls three metres high What should be the minimum size of a plane mirror fixed on the wall in front of him if he is to see the full height of the wall behind him 1 0 8 m 2 1 m 3 1 5 m 4 23 m

9 ALLE A symmetrical double convex lens is cut in two 3 equal parts by a plane containing the principal axis If the power of the original lens was 4D the power of a divided lens will be NCERT XII II 329 1 2 D 2 3D 3 4 D

Could you please tell me the effecti ve focal length of the system mirror formed Please provide stepwise explanation Q 2 Figure shows a concavo convex glass alg lens having radii of curvature of surfaces as R 120 cm R 60 cm The lens is placed upon a horizontal plane mirror Water afw and a liquid a are filled as shown Liquid Plane Mirror Lens Water

For a prism of refractive index 1 5 the angle of minimum deviation is equal to angle of prism Then prism angle will be 1 2 sin 3 4 2 2 cos 3 3 2 cos 1 3 4 3 NCERT XII II 331