Question 1 :
What is the power of the lens, if the far point of a short sighted eye is $200\ cm$?
Question 6 :
Which of the following term is not associated with a lens?
Question 7 :
Two thin lenses of focal lengths $f_{1} and f_{2}$ are in contact and coaxial. The power of the combination is :<br/>
Question 8 :
Find the power (with sign) of a concave lens of focal length $20cm$.<br/>
Question 10 :
Which of the following is not a characteristic of image formed by a Concave lens ?
Question 11 :
A real, inverted and equal in size image is formed by
Question 12 :
The frequency of a light wave in a material is $2\times 10^{14} Hz$ and wavelength is $5000\overset {\circ}{A}$. The refractive index of material will be :
Question 13 :
A focal length of a lens is 10 cm. What is power of a lens in dioptre?
Question 14 :
A plane glass plate is placed over a various coloured letters (violet, green, yellow, red). The letter which appears to raised more
Question 16 :
$ \dfrac{\sin i}{\sin r}  =$constant, the value of constant depends upon<br/>a) Pair of media <br/>b) Color of incident light<br/>c) Wave length <br/>d) Refracting nature of material<br/>
Question 17 :
What type of mirror can be used alone to obtain a real image of a real object?
Question 18 :
Which of the following are common to images formed by both Concave and Convex lens ?
Question 19 :
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 21 :
The mirror used in automobiles to see the rear field of view is
Question 22 :
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 23 :
A beam of light passing from air enters into the glass. Identify which of the following statements is true?<br/>
Question 24 :
State whether the following statement is True or False. <br/>A real image can be obtained by putting an object at any distance from a convex mirror
Question 25 :
During refraction through a glass block, the angle of refraction _______.
Question 26 :
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 27 :
A ray of light is incident on glass slab making an angle of incidence $sin^{-1} \left( \dfrac{\sqrt 3}{2} \right )$. What will be the angle of refraction in glass of refractive index 1.5?
Question 28 :
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 29 :
$0.04m$ of glass contains the same number of waves as $0.05m$ of water, when monochromatic light passes through them normally. Refractive index of water is $4/3$. Refractive index of glass is
Question 30 :
If a lens has power -2.5D, then it is a :
Question 32 :
A thin layer of water is transparent but a very thick layer of water is
Question 33 :
The far point of a myopic person is 40 cm. To see the distantobjects clearly, the focal length and the power of the lensused should be:
Question 34 :
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 35 :
If the angle of incidence increases gradually then angle of refraction also_______. <br/>
Question 36 :
A ray of light in a liquid of refractive index $1.4$ approaches the boundary surface between the liquid and air at an angle of incidence whose sine is $0.8$. Which of the following statement is correct about the behaviour of the light?
Question 37 :
When an object is moved along the principal axis of a thin converging lens of focal length 12 cm, two images, three times the size of the object are obtained when the object is at $x_1$ and $x_2$ distance from the lens. Which one of the following could be the value of the ratio $\frac {x_1}{x_2}$ ?
Question 38 :
The image of an object is formed by a convex lens. When that object is placed beyond the focal length is -
Question 39 :
A light ray travels from optically denser medium to optically rarer medium, if the angle of incidence and refraction at point of incidence are $\angle i$ and $\angle r$ respectively, then find the angle of deviation in terms of $\angle i$ and $\angle r$.
Question 41 :
The time from sunrise to sunset is lengthened by about 4 minutes on the earth because
Question 42 :
A glass slab is placed in the path of a beam of convergent light; the point of convergence of light
Question 43 : Gita arranges some mirrors in group- $1$ and group- $2$ according to the magnification, type of image and size of image from the following data.<table class="wysiwyg-table"><tbody><tr><td>Sr. No.</td><td>Group-$1$</td><td>Group-$2$</td></tr><tr><td>$(1)$</td><td>$<1$ and negative</td><td>Real, inverted and small</td></tr><tr><td>$(2)$</td><td>$>1$ and positive</td><td>Real, inverted and enlarged</td></tr><tr><td>$(3)$</td><td>$>1$ and negative</td><td>Virtual, erect and enlarged</td></tr><tr><td>$(4)$</td><td>$<1$ and positive</td><td>Virtual, erect and small</td></tr></tbody></table>For which of the pairs from the group $1$ and $2$ you disagree.
Question 44 :
A point on the principal axis of a lens, to which light rays parallel to the principal axis converge after passing through the lens, is ............
Question 46 :
If the angle of incidence is twice the angle of refraction in a medium of refractive index $\mu$, then the angle of incidence is :
Question 47 :
Refraction index of water is 4/3. Calculate speed of light in water.
Question 48 :
An object is placed on the principal axis of a concave mirror at a distance of 60 cm. If the focal length of the concave mirror is 40 cm then determine the magnification of the obtained image.
Question 49 :
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 51 :
Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?<br/>
Question 52 :
When white light is passed through two consecutive prisms, the resultant will be:
Question 56 :
When Astronauts fly at higher altitude, the sky appears dark because ;
Question 60 :
Why do high rise buildings have a red light on the top of the building?
Question 63 :
Long-sightedness is caused by the eyeball being too short. It can be corrected by the use of a :
Question 64 :
Fine beam of light entering through a small hole in a dark room illuminates the particles in its path. Identify the effect associated with this process.<br/>
Question 65 :
The sun appears red at the time of sun-rise and sun-set. This is because:
Question 66 :
A man can see vertical lines but he is unable to see the horizontal lines placed at the same distance. What type of lens he should use?
Question 67 :
The color of scattered light depends on ____ of the scattering particles.
Question 68 :
Fine beam of light entering through a small hole in a dark room illuminates the particles in its path. Identify the effect associated with this process.<br/>
Question 70 :
Which colour of light is scattered the most(maximum) in the atmosphere?
Question 72 :
The split of white light into its constituent colours, by a triangular prism, is known as:
Question 73 :
During dispersion through prism, red light travels fastest and violet travels slowest of all the seven colours. As a result:
Question 74 :
The spectrum, in which the colours are separated using a narrow source of light, is called:
Question 75 :
Some stars appear red in colour and some blue in colour. Which one of the statements is true?<br>
Question 79 :
Larger particles scatter light at the ____ end of the spectrum the least. <br/>
Question 81 :
Assertion: By roughening the surface of a glass sheet its transparency can be reduced. <br>Reason: Glass sheet with rough surface absorbs more light.
Question 83 :
Assertion: The setting sun appears to be red.
Reason: Scattering of light is directly proportional to the wavelength.
Question 84 :
What characteristic property of light is responsible for the blue colour of the sky?<br>
Question 86 :
At sun rise or at sun set the sun appears to be reddish while at mid day it looks white. This is because
Question 88 :
Assertion: The setting sun appears to be red.
Reason: Scattering of light is directly proportional to the wavelength.
Question 89 :
Assertion: The setting sun appears to be red. <br>Reason: Scattering of light is directly proportional to the wavelength.
Question 93 :
Which of the following phenomena cannot be explained by scattering of light ?
Question 94 :
At sunrise or sunset, the sun appears to be reddish white. This is because :
Question 95 :
Assertion: In the absence of atmosphere the sky would appear black.<br/>
Reason: Atmosphere scatters the light and hence we get blue colour.
Question 96 :
Assertion: Incoming light reflected by earth is partially polarized.
Reason: Atmospheric particle polarize the light.
Question 99 :
Assertion: By roughening the surface of a glass sheet its transparency can be reduced. <br>Reason: Glass sheet with rough surface absorbs more light.
Question 100 :
Which of the following phenomena cannot be explained by scattering of light ?
