Geometrical Optics Questions and Answers

A ray incident at a point at an angle of incidence of 60 enters a glass sphere of 3 and is reflected and refracted at the farther surface of the sphere The angle between the reflected and refracted rays at this surface is

A light ray is incident on a transparent sphere of index 2 at an angle of incidence 45 What is the deviation of a tiny fraction of the ray which enters the sphere undergoes two internal reflections and then refracts out into air

Two convex lenses A and B placed in contact form the image of a distant object at P If the lens B is moved to the right a little the image will AB a move to the left b move to the right c remain at P d move either to the left or right depending upon focal length of the lenses COMED P

The focal length of lens of a camera is 8 cm With it the photograph of an object of 1 m high is taken At what dis tance must the object be maintained from the lens of the camera so that the height of the image is 5 cm on the film What will be the distance of the film now from the lens 1 68 m 8 4 cm

6 The focal length of lens of a camera is 5 cm The distance of the lens from the photographic plate can be changed to obtain the image on the plate of the objects at different dis tances Find the range through which the lens has to move in order to bring objects into focus at distances beyond 20 5 cm cm from the plate

1 By placing a convex lens between an object and a screen an image magnified 3 times of its object is obtained on the screen By shifting the lens through a distance of 30 cm towards the screen again an image is obtained on the screen What is the focal length of the lens 11 25 cm

5 A convex lens forms an image of height 1 cm of an object on a screen Keeping the positions of the object and the screen unchanged the lens is shifted and a second image is formed on the screen If this image is of height 0 75 cm what is the height of the object have 0 87 cm

36 The image of point P when viewed from top of the slabe will be 1 5 cm p 1 5 1 5 P 1 2 0 cm above P 2 1 5 cm above P 3 2 0 cm below P 4 1 cm above P 1 5 cm 1 5 cm 12 cm 2801 12 36

2 If an object is placed in front of a convex lens at two differ ent positions the size of its real image is twice or thrice the size of the object respectively The difference of the dis tance between the two positions of the object is 5 cm What is the focal length of the lens 30 cm

An object is placed on the left side of a convex lens of focal length 16 cm at a distance of 8 cm from the lens Another convex lens of focal length 10 cm is placed coaxially on the right side of the first lens at a distance of 5 cm from it Determine magnification and position of the final image formed by the lens combination 20 at a distance of 19 09 cm behind the second lens

A plane mirror of length L moves about one of its ends P with constant angular velocity w anticlockwise A point object O is fixed where OP 2L The image of object 777777777777 moves on a circle of radius 2L centred at P with angular speed 2w clockwise moves on a circle of radius L centred at P with angular speed 2w clockwise 21 moves on a circle of radius 2L centred at P with angular speed 2w anticlockwise

wo concave mirrors with equal focal length f are placed one above other at a separation of d Upper mirror has a small hole at its centre as given A small object is placed at centre of lower mirror Take first reflection at above mirror and second at lower For final image to be at the hole of the upper mirror the value of d can be T

1 The image of a film is to be cast on a screen with a magni fication 50 times its height If focal length of the lens is 7 5 cm how far is the screen to be placed from the lens Under this condition what is the distance of the film from the lens 382 5 cm 7 65 cm

A convex lens of focal length 1 5 m is placed in a system of co ordinate axis such that its optical centre is at origin and principle axis coincide with the x axis An object O and a plane mirror are arranged on the principal axis as shown in figure Find the value of d in m so that y co ordinate of image after refraction and reflection is 0 3 m mirror 2 0 1 in m 2 5 m 4 m A B C 5 m D 2 4 m 1 1 0 0 d 1 1 0 tan 0 0 3 X

Two concave mirrors with equal focal length f are placed one above other at a separation of d Upper mirror has a small hole at its centre as given A small object placed at centre of lower mirror Take first reflection at above mirror and second at lower For final image to be at the hole of the upper mirror The value of d can be A 4 f B 2f C 3f D f 3 d TTT

Consider a system of two lenses L and L2 which are combined as shown 1 1 5 H2 2 0 All curved surfaces have equal radius of curvature of 20 cm One side of L2 is silvered An object of length 2mm is at a distance of 40 cm Consider paraxial rays All lenses are thin The final image formed by system is at a distance of cm from point P 2mm 40cm L L2 H1 H2 EP TTTTTIBET

glass slab is placed between an object O and observer The refractive index of glass slab varies with distance x from the face AB as Ho oser compared to original distance the object appears to the observer Consider normal incidence only t Eye 1 1 where Ho 1 How much

A glass slab is placed between an object O and observer The refractive index of glass slab varies with distance x from the face AB as o 1 1 where Ho 1 How much closer compared to original distance the object appears to the observer Consider normal incidence only Ot 1 ln2 Ot 1 ln2 Ot 2 ln2 Ot 2 ln2 B t D Eye

cross section of the glass prism has form of an isosceles triangle One of the equal faces is coated with silver A ray of light incident normally on the other equal faces and after getting Reflected twice emerges through the base of prism along the normal Find the angle of prism Y Y B A a

5 With reference to the figure given below match the items in Column I with terms Column II and choose the correct option from the codes given below Normal Incident ray Reflected ray Plane mirror Column I A Angle of reflection B Value of angle B C Angle of deviation of the incident rays a A 1 B 2 C 3 b A 3 B 2 C 1 c A 2 B 3 C 1 Column II 1 x 2 2 3 a

3 y A glass slab is kept over three coloured dots viz blue yellow and red If the coloured dots are viewed from the top then the dot appearing closest to the eye will be 1 Red 3 Blue 2 Yellow All equally close factor is maximum in an LCR series circuit LAYA

A lens of focal length fis cut along the diameter into two identical halves In this process a layer of the lens t in thickness is lost then the halves are put together to form a composite lens Im between the focal plane and the composite lens a narrow slit is placed near the focal plane The slit is emitting monochromatic light with wavelength 2 Behind the lens a screen is located at a distance L from it NDUZ 3234 1 3 tf 2 1 2 d Lt 2f S S S optics an Find the fringe width for the pattern obtained under giver arrangement on the screen af 425 25 2t p V D 4 L number 19 The expression for the number of visible maxima which are obtained through above said arrangement will turn out to be 2 tf 22 dk 2L12 2f

Three slabs are joined and kept in front of concave mirror of radius of curvature of 3 150 cm The entire system is submerged in water water 20cm kept at distance at 20 cm from first slab on the principal axis as shown The distance of final image formed by this system from pole of mirror P is found to be 150 x cm The value of x is H 1 5 1 H3 1 5 1 9 H2 13 45cm 24cm 54cm P 1 10cm A point object is

he path of a ray of light passing through an equilateral prism ABC is shown in the figure The ray of light is incident on face BC at an angle just greater than Critical angle for total internal reflection to take place The total angle of deviation after the refraction at face AC is 120 The value of refractive index of material prism is x The value of x is A

e A ray of light from water to glass passes straight without bending 1 1 0 Angel of incidence i900 Angle of itidence is Refractive ide of quid ad glas is same Angle of noidenc is equal tortica ingle X but the light ray may even pass undeviat ed when passed through 2 different med ia of same refractive indices then option

Plane screen 2 Elliptical 4 Hyperbolic 1 Parabolic 3 Circular Young s double slit experiment is performed with monochromatic light A thin film is introduced in front of one of the slits 1 Intensity at the position of central maxima must decrease 2 Intensity at the position of central maxima may increase 3 Central maxima may remain unshifted 4 Intensity at position of first maxima may decrease In the Young s arrangement screen starts moving towards right with constant speed v Initial distance between screen and plane of slits is x At t 0 1ot ordor maxima is lying at point A After how 1 10 6 m 3 10 10 m De observe When white light is incic of thickness 10 cm an the wavelength whic reflected system of lig 1 7000 A 3 4000 A Imperfections in op with the help of 1 Newton s Ring 2 Fresnel s Bip 3 Lloyd s singl 4 Young s do 29 Two light rays vacuum are in travels a path

plz tell me what are these 2 formulas for and what is re solution power of microscope and telescope 01 We can apply a similar argument to the objective lens of a microscope Fig 10 19 A detailed analysis shows that the radius of the In this case the object is placed slightly beyond f so that a real image is region is approximately given by formed at a distance u Fig 10 20 The magnification ratio of image size to object size is given by mu f It can be seen from Fig 10 20 that cons ht ru 1 brig 103 D f 2 tan B 10 26 where 23 is the angle subtended by the diameter of the objective lens at the focus of the microscope Object Object plane f Objective lens Image 11 22 2 D Image plane To FIGURE 10 20 Real image formed by the objective lens of the microscope 1 22Af 0 61Af 2a a 2a FIGURE 10 19 A parallel beam of light is incident on Because of diffraction effects the beam gets focu 373

4 bottom of beaker containing water water 3 36cm from pole of lens and mirror is at 100 cm from lens f 30 cm A 105 cm 36 cm B 85 cm 100 cm 20 cm The value of H is given that O C 215 cm H D 100 cm

A ray of light is incident on a prism of angle A and refractive index u will not emerge out of prism for any angle of incidence if 1 sin 2 cos A 3 4 4 sin A 23

Options The focal length of a concave mirror is 30 cm Find the position of the object in front of the mirror on axis so that image is three times the size of the object 11 Solution Answer 4 1 1 1 f m 40 cm 20 cm 50 cm 30 Both 20 cm and 40 cm are possible 1 1 1 V u v 3u

Consider a particle moving towards convex mirror along its principal axis with velocity 10 m s as shown The velocity of the mirror is 2 m s The velocity of particle with respect ground is m s 4 10cm 10m s 2m s f 10cm

Consider a system of two lenses L and L which are combined as shown 1 5 1 2 0 All curved surfaces have equal radius of curvature of 20 cm One side of L is silvered An object of length 2mm is at a distance of 40 cm Consider paraxial rays All lenses are thin The final image formed by system is at a distance of from point P cm L L LA 40cm H1 H 2mm P

Consider a system of two lens seperated by distance d A point object P is kept in front of diverging lens L L is convex lens Both lenses are thin f 6 cm f 12 cm L L Object P 12cm Choose the correct statement s If d 8 cm then final image is formed at infinity If d 12 cm then final image is formed at infinity The image formed by Lens L is virtual and at a distance of 4 cm from L The image formed by lens L is real and at a distance of 4 cm from L

3 A compound microscope has its length L and focal lengths of its objective and eyepiece are fo and fe respectively If least distance of distinct vision is D then for normal adjustment its magnification may be approximated as 1 f fE L D 2 LD fo fE 3 fo fE LD L D 4 f fg fo E

7 A glass slab is kept over three coloured dots viz blue yellow and red If the coloured dots are viewed from the top then the dot appearing closest to the eye will be 1 Red 3 Blue 2 Yellow 4 All equally close

6 A thin biconvex lens is kept on a plane mirror When an object is kept at 20 cm in front of the lens its image is formed at the same point The focal length of the convex lens is 1 10cm 2 20cm 3 40cm 4 80cm

The image of point P when viewed from top of the slabe will be 1 2 1 5 cm 3 1 5 1 5 P 2 0 cm above P Question Type Single Correct Type 1 5 cm above P 2 0 cm below P 1 5 cm 2 cm 1 5 cm

The critical magnetic field for a solid in superconducting state a does not depend upon temperature c increases if the temperature decreases b increases if the temperature increases d does not depend on the transition temperature

A glass prism of refractive index is kept in air as shown in the figure An incident ray strikes at face AB at point M at an angle of incidence i A is the angle of prism Choose the correct statement Air B 90 A M H Air C O For all values of angle of incidence i the ray will emerge out from face AC if sin A 1 O For all values of angle of incidence i the ray will not emerge out from face AC if u sin A 2 1 If A 45 and 2 the maximum deviation will occur at i 0 If A 60 and 2 the minimum deviation will occur at i 60

the magnification formula is ha ving a negative sign before it plzz explain why it is there As i know that magnification formula is m f f u Why it is m f f u Jun 23 2021 7 20 02 PM Answer The focal length of a convex lens is F An object is placed at a distance x from the focus as shown in the figure below The magnitude of the magnification is 3 m m focal length AF 4 Answered 2

Three rays of light namely red R green G and blue B are incident on the face PQ of a right angled prism PQR as shown in the figure B G R P Q R The refractive indices of the material of the prism for red green and blue wavelength are 1 27 1 42 and 1 49 respectively The colour of the ray s

15 A point source S is placed at the bottom of a transparent block of height 10 mm and refractive index 2 72 It is immersed in a lower refractive index liquid as shown in the figure It is found that the light emerging 1 S Liquid Block from the block to the liquid forms a circular bright spot of diameter 11 54 mm on the top of the block The refractive index of the liquid is a 1 21 b 1 30 c 1 36 d 1 42 JEE Adv 2014

in front of the centre of a mirror of width d hung vertically on a wall A man walks in front of the mirror along a line parallel to the mirror at a distance 2 L from B TLA 2L it as shown in the figure The greatest distance over which he can see the image of the light source in the mirror is a d 2 c 2 d b d d 3d for a con the objec from the inverted line wit towards object p a x c a FIT 20001 8 A media showr paralle

Two thin symmetrical lens of different nature have equal radii of curvature of all faces R 20 cm The lenses are put close together and immersed in water The focal length of the system is 24 cm The difference betwe refractive indices of the two lenses is Refractive index of water is Of

Time taken by a ray of light to travel through a glass slab of thickness 10 cm and refractive index 1 5 will be Take c 3 108 m s 4 5 x 10 10 S 10 7 s 5 x 10 8 s 5 x 10 10 s

View In English The graph shows how the reciprocal of magnification produced by a converging thin lens varied with object distance u in displacement method What was the focal length of the lons used A O No 20 1 2 4 Correct Answer 3 Status unattempted a b bc a c D ab c V to Bookmark Fist

A glass sphere 391 has a radius of curvature 20 cm Half of the surface of the sphere is now silvered A small object is now placed at a distance of 40 cm from the unsilvered surface of the sphere on the axis of the spherical mirror formed Find the location of the final image formed

O 15 cm A concave mirror is moving with velocity 41 27 cm s1 whereas a point object is moving with 81 11j cms 1 as shown in figure The object is at a distance of 15 cm in front of mirror whose focal length is 10 cm The axial velocity of image is then 4xn find the value of n Answer 0 0 O 0 X 01 02 03 04 05 06 07 08 01 02 03 04 05 06 07 08 09 09

An object is moving with velocity as shown in figure If and V are velocities of two images in two plane mirrors M and M respectively such that V V V 0 then 0 is in degrees is 0 V M 0 60

A point source is kept at the centre of a cube made of a transparent material of refractive index u 1 5 and side meter The total minimum surface area in m a painted of the cube so that the source is not visible from outside of cube