Question 1 :
Which of the following lens is used to minimise hypermetropia ?
Question 2 :
The sun appears red at the time of sun-rise and sun-set. This is because:
Question 4 :
The sun appears red at the time of sun-rise and sun-set. This is because:
Question 6 :
An astronaut in a spaceship the sky appears black due to:
Question 7 :
Intensity of light ray in a directionafter scattering by small particles (smaller than wavelength):
Question 9 :
For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index lies between:
Question 13 :
The path of a beam of light is invisible in which solution?
Question 15 :
Assertion: A beam of white light gives a spectrum on passing through a hollow prism.
Reason: Speed of light outside the prism is different from the speed of light inside the prism.
Question 16 :
What is the time difference between actual sunset and apparent sunset?
Question 18 :
A person cannot see fundamental colours (red, blue, green). This defect is called:
Question 20 :
The inability among the elderly to see nearby objects clearly because of the weaking of the ciliary muscles is called
Question 23 :
Fill in the blank spaces by choosing the correct word.A prism is a piece of transparent material having three rectangular surfaces and .......... triangular surfaces.
Question 24 :
Name the prism required for obtaining the spectrum of infra red radiation<br/>
Question 25 :
In context of scatteringFine particles : ____ wavelength : : large particles : _____ wavelength
Question 26 :
What are the colours of the Sun observed most during sunrise/sunset and noon? <br/>
Question 30 :
The angle between the two refracting surface of a prism is called angle of :<br/>
Question 32 :
In the white light of sun, maximum scattering by the air molecules present in the earth's atmosphere is for:<br>
Question 34 :
When Astronauts fly at higher altitude, the sky appears dark because ;
Question 38 :
The danger signals installed at the top of tall buildings are red in colour. These can be easily seen from a distance because among all other colours, the red light:<br/>
Question 41 :
Which of the following quantities changes during the process of scattering?
Question 44 :
Which of the following lens is used to minimise myopia ?
Question 45 :
A defect, in which a person suffering from is unable to see in all directions equally well, is:
Question 48 :
Some stars appear red in colour and some blue in colour. Which one of the statements is true?<br>
Question 53 :
Assertion: A Diamond sparkles more than a glass imitation cut to the same shape.
Reason: The refractive index of diamond is less than that of glass.
Question 56 :
Assertion: The setting sun appears to be red.
Reason: Scattering of light is directly proportional to the wavelength.
Question 57 :
When is the direction of scattered light independent of the wavelength?
Question 58 :
Larger particles scatter light at the ____ end of the spectrum the least. <br/>
Question 60 :
At sun rise or at sun set the sun appears to be reddish while at mid day it looks white. This is because
Question 61 :
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 62 :
Assertion: In the absence of atmosphere the sky would appear black.<br/>
Reason: Atmosphere scatters the light and hence we get blue colour.
Question 63 :
Larger particles scatter light at the ____ end of the spectrum the least. <br/>
Question 64 :
Assertion: Incoming light reflected by earth is partially polarized.
Reason: Atmospheric particle polarize the light.
Question 65 :
Assertion: The setting sun appears to be red.
Reason: Scattering of light is directly proportional to the wavelength.
Question 68 :
At sunrise or sunset, the sun appears to be reddish white. This is because :
Question 70 :
In a beaker containing colloidal solution of sodium thiosulphate and a drop of con. sulphuric acid, light observed from side of beaker is:
Question 72 :
Which of the following phenomena cannot be explained by scattering of light ?
Question 73 :
Assertion: Incoming light reflected by earth is partially polarized.
Reason: Atmospheric particle polarize the light.
Question 77 :
Assertion: The setting sun appears to be red. <br>Reason: Scattering of light is directly proportional to the wavelength.
Question 78 :
Assertion: In the absence of atmosphere the sky would appear black.<br/>
Reason: Atmosphere scatters the light and hence we get blue colour.
Question 79 :
Assertion: Fine particles in atmosphere scatter the light of shorter wavelength more.
Reason: Sky appears blue.
Question 81 :
Which of the following phenomena cannot be explained by scattering of light ?
Question 82 :
In a beaker containing colloidal solution of sodium thiosulphate and a drop of con. sulphuric acid, light observed from side of beaker is:
Question 83 :
Assertion: A Diamond sparkles more than a glass imitation cut to the same shape.
Reason: The refractive index of diamond is less than that of glass.
Question 84 :
When is the direction of scattered light independent of the wavelength?
Question 87 :
At sunrise or sunset, the sun appears to be reddish white. This is because :
Question 88 :
During scattering of light, the amount of scattering is inversely proportional to ________ of wavelength of light.
Question 89 :
Assertion: Bluish colour predominates in a clear sky, since blue has a shorter wavelength and is scattered strongly.
Reason: Blue has the shortest wavelength among all colours.
Question 91 :
Assertion: Fine particles in atmosphere scatter the light of shorter wavelength more.
Reason: Sky appears blue.
Question 93 :
What characteristic property of light is responsible for the blue colour of the sky?<br>
Question 97 :
Assertion: A piece of red glass is heated till it glows in dark. The colour of glowing glass would be orange.
Reason: Red and orange is complementary colours.
Question 98 :
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 :
Assertion: The setting sun appears to be red. <br>Reason: Scattering of light is directly proportional to the wavelength.
Question 101 :
One of the following is not an example of incomplete sex-linkage
Question 102 :
A normal eye is not able to see objects closer than $25$cm because?
Question 104 :
A person is wearing spectacles with concave lenses for correcting vision. While not using the glasses, the image of a distant object in his case will be formed<br>
Question 105 :
Two point white dots are 1 mm apart on a black paper. They are viewed by eye of diameter $3\ mm $.<br/>Approximately, what is the maximum distance at which these dots can be resolved by the eye?<br/>[ take wavelength of light >500nm]
Question 107 :
The process of re-emission of absorbed light in all directions with different intensities by the atom or molecule is called ____________.
Question 110 :
Myopia or near sightedness is a defect of eyes in which<br>
Question 113 :
The process of re-emission of absorbed light in all directions with different intensities by the atom or molecule is called ____________.
Question 114 :
The angular magnification of telescope is $30$. If all the light which passes through objective lens of diameter $80 cm$ also passes through eye piece lens then find out diameter of eye piece lens.
Question 115 :
The defective condition of accommodation of the eye in which distant objects are clearly seen but near objects are indistinct is<br>
Question 116 :
When the light rays converge at a point in front of the retina and then divert to form a blurred image on it, the defect is known as<br>
Question 117 :
In old age farsightedness is a defect of eye in man, in which
