Question 2 :
The maximum magnification that can be obtained with a convex lens of focal length $$2.5\ cm$$ is ( the least distance of distinct vision is $$25\ cm$$)
Question 3 :
When a drop of oil is spread on a water surface, it displays beautiful colours in daylight because of :
Question 5 :
No matter where the object is placed in front of a mirror, the image formed is virtual, erect and smaller than the object. This mirror must be:
Question 7 :
Which of the following is not a characteristic of image formed by a Concave lens ?
Question 8 :
A ray of light passing through the .......... of the lens, passes on undeviated.
Question 10 :
A ray of light passes through a glass slab. and the angle of emergence is found smaller than the angle of incidence. So, we may conclude that the glass slab
Question 11 :
When an object is at infinity from a concave mirror, the image formed is
Question 12 :
A beam of light passing from air enters into the glass. Identify which of the following statements is true?<br/>
Question 14 :
State whether given statement is True or False<br/>A ray of light incident parallel to the principal axis of a lens, passes undeviated after refraction.<br/>
Question 15 :
In case of a real and inverted image, the magnification of a mirror is:
Question 16 :
The mirror used in automobiles to see the rear field of view is
Question 17 :
When a ray of light passes from an optically less dense medium to a more dense medium, it :
Question 18 :
The radius curvature for a convex lens is $$40\ cm$$, for each surface. Its refractive index is $$1.5$$. The local length will be
Question 19 :
When a ray of light passes through a rectangular slab, made up of some transparent material other than glass, the emergent ray is
Question 20 :
If the light moving in a straight line bends by a small but fixed angle, it may be a case of<br>$$(i)$$reflection<br>$$(ii)$$refraction<br>$$(iii)$$diffraction<br>$$(iv)$$dispersion<br>
Question 21 :
The focal length of convex lens is 30 cm and the size of image is quarter of the object, then the object distance is:-
Question 22 :
Assertion: If refractive index of one medium is equal to refractive index of second medium, then beam does not bend at all.
Reason: The bending of light does not depend on refractive indices of media.
Question 23 :
Lens A produces a magnification of -0.8 whereas lens B produces a magnification of +0.8. Which one of the following applies to lenses A and B?
Question 24 :
State whether true or falseA convex mirror is used for obtaining a real and magnified image.
Question 25 :
State whether true or false.<br/>A concave mirror always forms erect and diminished images.
Question 26 :
A photograph of a horse is taken by a camera whose lens has been painted with black stripes. The photograph will be of a :
Question 27 :
If $$f$$ is the focal length of a lens, then the power of the lens is equal to
Question 29 :
The power of a lens having a focal length of $$1\;cm$$ is :
Question 30 :
The focal length of a convex lens is $$5\,cm$$,where should the object be placed to get  a real image with same size as that of object:
Question 31 :
Choose the correct statement(s) related to the motion of object and its image in the case of  mirrors.
Question 32 :
State whether true or false : A concave lens will always give a virtual, erect and diminished image.
Question 33 :
The constant ratio of the sine of angle of incidence to the sine of angle of refraction is also known as:
Question 34 :
Fill in the blank. A _____ is a piece of transparent glass bounded by two spherical surfaces. 
Question 35 :
Due to refraction, sunrise appears ______ sun comes to horizon and sunset appears______sun leaves horizon respectively.
Question 36 :
State whether true or false.<br/>The images formed by a convex mirror are always erect and enlarged.
Question 37 :
The power of two convex lenses $$A$$ and $$B$$ are $$8$$ diopters and $$4$$ diopters respectively. If they are to be used as a simple microscope, the magnification of
Question 38 :
Ratio of the size of the image to the size of the object is known as:
Question 42 :
A real image, equal in size to the object, is obtained when the object is placed at the centre of curvature in front of which mirror?
Question 43 :
The power of a lens being $$+4$$ dioptres suggests that it is a
Question 44 :
A focal length of a lens is 10 cm. What is power of a lens in dioptre?
Question 45 :
A man is unable to see closer than 1 m clearly.The power of lenses of his spectacles should be to see nearby object.
Question 46 :
In order to get a diminished virtual image, the object can be placed anywhere in front of a :
Question 47 :
The distance between an object and its real image produced by a converging lens is $$0.72\ m$$. The magnification is $$2$$. What will be the magnification when the object is moved by $$0.04\ m$$ towards the lens?
Question 49 :
The power of a lens whose focal length is one metre is ______ dioptre.
Question 51 :
A beam of red light ($$7000$$ A.U. in air) in passing from air into a medium making an angle of incidence of $$61^o$$ and angle of refraction of $$34^o$$. find the wavelength of red light in the medium.
Question 52 :
State whether true or false :A transparent material bound by two surfaces, of which one or both surfaces are spherical, forms a lens.
Question 53 :
An object is placed upright on the axis of a thin convex lens at a distance of four focal lengths ($$4f$$) from the center of the lens. An inverted image appears at a distance of $$\dfrac{4}{3} f$$ on the other side of the lens. What is the ratio of the height of the image of the height of the object?
Question 55 :
A simple magnifying lens is used in such a way that an image is formed at $$25\ cm$$ away from the eye. In order to have $$10$$ time magnification, the focal length of the lens should be
Question 56 :
A beam of monochromatic blue light of wavelength $$4200\mathring { A } $$ in air travels in water of refractive index $${ 4 }/{ 3 }$$. Its wavelength in water will be
Question 57 :
A double convex lens of glass of $$\mu_1.5$$ has radius of curvature of each of its surface is $$0.2\ m$$. The power of the lens is
Question 58 :
An object of length $$6\ cm$$ is placed on the principle axis of a concave mirror of focal length $$f$$ at a distance of $$4\ f$$. The length of the image will be
Question 59 :
An object is placed at a distance of $$20\ cm$$ from a convex lens of focal length $$10\ cm$. The image is formed on the other side of the lens at a distance
Question 60 :
A straight line graph is obtained by plotting sine of angle of incidence versus sine of angle of refraction. The slope of this graph represents :
Question 61 :
A convex lens of focal length $$84\ cm$$ is in contact with a concave lens of focal length $$12\ cm$$. The power of combination (in diopters) is
Question 62 :
A person cannot see objects clearly beyond $$2.0\ m$$. The power of lens required to correct his vision will be
Question 63 :
The image of an object placed in front of a concave mirror of focal length 12 cm is formed at a point which is 10 cm more distant from the mirror than the object. The magnification of the image is:<br/>
Question 64 :
A thin layer of water is transparent but a very thick layer of water is
Question 65 :
A lens which has focal length of $$4\ cm$$ and refractive index of $$1.4$$ is immersed in a liquid of refractive index $$1.6$$, then the focal length will be
Question 66 :
The least distance of vision of a longsighted person is $$60\ cm$$. By using a spectacle lens, this distance is reduced to $$12\ cm$$. The power of the lens is
Question 67 :
Convex lenses are used in peepholes of house doors for security to provide a view of people or objects outside the doors. Is this statement true or false?<br/>
Question 68 :
A film projector magnifies a $$\displaystyle 100\ { cm }^{ 2 }$$ film strip on a screen. If the linear magnification is $$4$$, the area of the magnified film on the screen is be $$\displaystyle 1000\ { cm }^{ 2 }$$
Question 69 :
Light of frequency $$\nu$$, wave length $$ \lambda $$ travelling with a velocity $$v$$ enters into a glass slab of refractive index $$ \mu $$ then frequency, wave length and velocity of the wave in glass slab respectively are :<br/>
Question 70 :
The image of an object formed by a convex lens when the object is placed between the lens and the focal point is -
Question 71 :
Convex lens forms a real, point sized image at focus, the object is placed
Question 72 :
You are given water, mustard oil, glycerine and kerosene. In whichof these media a ray of light incident obliquely at same angle wouldbend the most ?<br>
Question 73 :
The $$X-Z$$ plane separates two media $$A$$ and $$B$$ of refractive indices $$\mu_{A}=1.5$$ and $$\mu_{B}=2.$$ A ray of light travels from $$A$$ to $$B$$, its direction in two media are given by unit vectors. $$\hat {u}_{A}=a\hat {i}+b\hat {j}$$ and $$\hat {u}_{B}=c\hat {i}+d\hat {j}$$ respectively, then :<br/>
Question 76 :
Height of the image of an principal axis produced by a convex lens is double the object height . If the focal length of the lens is $$20 cm$$, then the image distance from lens is :
Question 77 :
Find out the correct option from the following.<br>(a) The magnification is positive for all virtual images and is negative for all real images.<br>(b) The magnification of concave lens and convex mirror is always positive where as the magnification of convex lens and concave mirror can be positive or negative depending on the position of the object before the lens.<br>
Question 78 :
A ray of light travelling inside a rectangular glass block of refractive index $$\sqrt 2$$ is incident on the glass-air interface at an angle of incidence of $$45^o$$. The refractive index of air is one. Under the these conditions the ray will
Question 79 :
The linear magnification for a spherical mirror is the ratio of the size of the image to the size of the object, and is denoted by m. Then m is equal to (symbols have their usual meanings)
Question 80 :
A ray of light falls on a transparent glass slab of refractive index $$1.62$$. What is the angle of incidence, if the reflected ray and reflected ray are mutually perpendicular ?
Question 81 :
In passing through a boundary, refraction will not take place if:
Question 82 :
A concave mirror produces $$2$$ times magnified real image of an object placed at $$5 cm$$ in front of it. Where is image located?
Question 83 :
Two co-axial lenses of power $$+4D$$ and $$-2D$$ are placed in contact. The focal length of combination is
Question 84 :
A object is placed at 30 cm on the principle axis of the convex lens from the lens and an image is formed 60 cm from the lens. If focal length of the lens is 20 cm then calculate the magnification.
Question 85 :
A ray of light is incident from one medium $$(\mu = 1.5)$$ into another medium. If the angle of incidence and refraction are, respectively,$$60$$and$$45$$, thenwhatwill be the refractive index of the denser medium?
Question 86 :
A boy uses spectacles of focal length 60 cm. Name the defect of vision he is suffering from which lensis used for the correction of this defect? Compute the power of this lens
Question 87 :
If the angle of incidence increases gradually then angle of refraction also_______. <br/>
Question 88 :
Frosted glass is widely used for translucent windows. The region where a transparent adhesive tape is stuck over the frosted glass becomes transparent. The most reasonable explanation for this is :
Question 90 :
A convex mirror of focal length $$f$$ forms an image which is $$\cfrac { 1 }{ n } $$ times the object. The distance of the object from the mirror is :
Question 91 :
A plano-concave lens is made of glass of refractive index $$1.5$$ and the radius of curvature of its curved face is $$100 cm$$. What is the power of the lens?<br/>
Question 92 :
The image formed by objective lens of compound telescope will be:
Question 93 :
The expression for the magnification of a spherical mirror in the terms of focal length (f) and the distance of the object from mirror (u) is
Question 94 :
A beam of light passes through a sheet of plastic and out into the air. The beam makes $${\theta}_{1}$$ angles with the normal as it passes through the plastic and the angle the beam of light makes with the normal as it passes into the air is $${\theta}_{2}$$. The refractive index for air is $$1$$ and The refractive index for plastic is $$2$$.<br/>Calculate the value of $$\sin{{\theta}_{2}}$$, in terms of $${\theta}_{1}$$?
Question 95 :
A lens forms a diminished and erect image of an object. The magnification is $$\frac {1}{4}$$. Find ratio of distance between object and focus and focus and image<br>
Question 96 :
The image of an object is formed by a convex lens. When that object is placed beyond the focal length is -
Question 97 :
The power of a lens is a measure of its degree of
Question 98 :
The sun subtends an angle of $$(1/2)^o$$ at earth.The image of the sun is obtained on a screen using a converging lens of focal length 1.5 cm.The diameter of the image will be :
Question 99 :
A slide projector gives a magnification $$10.$$ If a slide of dimensions $$3$$ cm $$\times$$ $$2$$ cm is projected on the screen the area of image screen is
Question 100 :
A concave lens always gives a virtual image. In opticallenses worn by humans which of the following statementsis true ?
Question 101 :
A flim projector magnifies a flim of area $$100 $$ square centimeter on screen. If linear magnification is $$4$$ then area of magnified image on screen will be-
Question 102 :
When a light of wavelength $$4000$$ $$\displaystyle \overset { \circ  }{ A } $$ in vacuum travels through the same thickness in diamond and water separately, the difference in the number of waves is $$200$$. Find the thickness, if refractive indices of diamond and water are $$\displaystyle \frac { 5 }{ 2 } $$ and $$\displaystyle \frac { 4 }{ 3 } $$ respectively.
Question 103 :
Three convex lenses are available having focal lengths of $$4 cm, 40 cm$$ and $$4 m$$ respectively. Which one could be used as magnifying glass?
Question 104 :
Air has refractive index $$1.0003$$. Find the thickness of air column which will contain one more wavelength of yellow light of $$6000$$ $$A^0$$ than in same thickness of vacuum.
Question 105 :
An object is placed at $$30$$ cm distance from a concave mirror of focal length $$20$$ cm, then nature, magnification of the image will be:
Question 106 :
A short linear object of length $$b$$ lies along the axis of a concave mirror of focal length $$f$$ at a distance $$u$$ from the pole of the mirror. The size of the image is approximately equal to:<br/>
Question 107 :
A spherical convex surface separates object and image space of refractive index $$1$$ and $$4/3$$ respectively. If radius of curvature of the surface s $$0.1\ m$$, its power is
Question 108 :
A water film is formed on a glass-block. A light ray is incident on water film from air at an angle of$$\displaystyle { 60 }^{ \circ }$$ with the normal. The angle of incidence on glass slab is<br>($$\displaystyle { \mu }_{ g } = 1.5,{ \mu }_{ w } = \frac { 4 }{ 3 }$$)
Question 110 :
A short linear object of length $$b$$ lies along the axis of a concave mirror of focal length $$f$$ at a distance u from the pole of the mirror. The size of the image is approximately equal to :<br>
Question 111 :
An image of a bright square is obtained on a screen with the aid of a convergent lens. The distance between the square and the lens is $$40\ cm$$. The area of the image is nine times larger than that of the square. Select the correct statement(s).
Question 112 :
What happens when a ray of light is made to fall on a mirror along the normal?<br/>
Question 113 :
A ray of light going towards the centre of curvature of a convex mirror ............
Question 114 :
The distance between an object and its doubly magnified image by a concave mirror is: [ Assume $$f$$ = focal length]
Question 115 :
A $$4.5 cm$$ needle is placed $$12 cm$$ away from a convex mirror of focal length $$15 cm$$. Find the location of the image and the magnification.
Question 116 :
The magnitude of focal length of a concave mirror is $$f$$. An object is placed at a distance $$x$$ from the focus and forms a real image. The magnification is:<br/>
Question 117 :
A concave shaving mirror has a radius of curvature of 35.0 cm. It is positioned so that the (upright) image of a mans face is 2.50 times the size of the face. How far is the mirror from the face?
Question 118 :
The image obtained while finding the focal length of convex lens is...................
Question 119 :
The reflecting surface is given by $$y = \dfrac{10L}{\pi} \sin \dfrac{\pi x}{5L}$$. The co-ordinates of the point where a horizontal ray becomes vertical after reflection is:
Question 120 :
A $$2.5$$ dioptre lens forms a virtual image which is $$4$$ times the object placed perpendicularly on the lens. Then the required distance of the object from the lens is .
Question 121 :
The final image in an astronomical telescope is _______ the original object . Fill in the gap.<br/>
Question 122 :
The angle between the incident ray and the normal is called ________.<br>
Question 123 :
Image of an object at infinity is formed by a convex lens of focal length $$30 \ cm$$ such that the size of the image is $$2 \ cm$$. If a concave lens of focal length $$20\  cm$$ is placed in between the convex lens and the image, at a distance $$26\  cm$$ from the convex lens, size of the new image is:
Question 124 :
A symmetric double convex lens is cut in two equal parts by a plane containing the principal axis. If the power of the original lens was 4 D, the power of a divided lens will be
Question 125 :
In vacuum, to travel distance 'd', light takes time 't' and in medium to travel distance $$'5d'$$, it takes time 'T'. The critical angle of the medium is.<br>
Question 126 :
A point object is placed on the principal axis of the convex lens of focal length 20cm at a distance 40 cm to the left on it. The diameter of the lens is 10cm. If the eye is placed 60cm to the right of the lens at a distance h below the principal axis, then max value of 'h' to see the image is
Question 127 :
Two thin lenses of power $$+3.5D, -2D$$ are placed in contact. Find the power of lens combination.
Question 128 :
The glancing angle of incidence is $$10^{\circ}$$. What will be the glancing angle of reflection?
Question 129 :
The diameter of the reflecting surface of spherical mirror is called ..............
Question 130 : In the table below, column I lists various mirrors  and lenses and column II their uses, qualities or properties.<br/><table class="wysiwyg-table"><tbody><tr><td>column  I</td><td>Column II</td></tr><tr><td>I. Plane mirror</td><td>A. Feels thinner in the middle.</td></tr><tr><td>II. Concave mirror</td><td>B. Always forms virtual image.</td></tr><tr><td>III. Convex mirror</td><td>C. Always forms virtual image of smaller size.</td></tr><tr><td>IV. Concave lens </td><td>D. Is used by dentists to examine teeth.</td></tr><tr><td>V. Convex lens</td><td>E. Can be used as reading glass.<br/></td></tr></tbody></table>The correct matching is:
Question 131 :
A small object of linear dimension $$x$$ lies on the axis of an optical mirror of local length $$f$$ at a distance $$a$$ from mirror. The linear dimension of image:
Question 132 :
Aconvex lens of radii of curvature 20 cm and 30 cm respectively. It is silveredat the surface which has smaller radius of curvature. Then it will behave as $$(\mu_g\, = \, 1.5)$$
Question 133 :
Let the x-z plane be the boundary between two transparent media. Medium $$1$$ in $$z\ge 0$$ has a refractive index of $$\sqrt { 2 } $$ and medium $$2$$ with $$z< 0$$ has refractive index of $$\sqrt { 3 } $$. A ray of light in medium $$1$$ given by the vector $$\vec { A } =6\sqrt { 3 } \hat { i } +8\sqrt { 3 } \hat { j } -10\hat { k } $$ is incident on the plane of separation. The angle of refraction in medium $$2$$ is:
Question 134 :
The focal length of a thin biconvex lens is 20 cm. when an object is moved from a distance of 25 cm in front of it to 50 cm, the magnification of its image changes from $$m_{25}$$ to $$m_{50}$$. The ratio of $$m_{25}$$ to $$m_{50}$$ is :
