Question 6 :
Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?<br/>
Question 10 :
The bluish colour of water in deep sea is due to:<br/>
Question 13 :
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 15 :
In context of scatteringFine particles : ____ wavelength : : large particles : _____ wavelength
Question 16 :
Long-sightedness is caused by the eyeball being too short. It can be corrected by the use of a :
Question 17 :
When white light is passed through two consecutive prisms, the resultant will be:
Question 18 :
The rising and setting of sun appear red because of : 
Question 19 :
If the power of an eye lens increases, then the defect of vision so produced is known as
Question 20 :
Some stars appear red in colour and some blue in colour. Which one of the statements is true?<br>
Question 21 :
When Astronauts fly at higher altitude, the sky appears dark because ;
Question 23 :
Name the prism required for obtaining the spectrum of ultraviolet light:<br/>
Question 24 :
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 25 :
Why do high rise buildings have a red light on the top of the building?
Question 26 :
The least distance of distinct vision for a defective eye is $75$ cm. What should be the focal length of the lens which will be used to read a book clearly at $25$ cm?
Question 32 :
CV Raman got the Nobel Prize for his experiment on :
Question 33 :
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 34 :
By which optical phenomena the splitting of white light into seven constituent colours occur?<br>
Question 38 :
Why astronauts see dark sky in space unlike blue sky on earth:
Question 39 :
Which of the following quantities changes during the process of scattering?
Question 42 :
Which colour of light is scattered the most(maximum) in the atmosphere?
Question 43 :
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 46 :
Which of the following lens is used to minimise myopia ?
Question 47 :
In the white light of sun, maximum scattering by the air molecules present in the earth's atmosphere is for:<br>
Question 48 :
Name the prism required for obtaining the spectrum of infra red radiation<br/>
Question 49 :
If the image of distant objects is formed in front of the retina, the defect of vision may be
Question 50 :
Why are red coloured lights are used in traffic signals to stop the vehicles?