Question Text
Question 1 :
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 2 :
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 5 :
What are the colours of the Sun observed most during sunrise/sunset and noon? <br/>
Question 6 :
Which of the following phenomena contributes significantly to the reddish appearance of the sun at sunrise or sunset?<br/>
Question 7 :
Which colour of light is scattered the most(maximum) in the atmosphere?
Question 8 :
The path of beam of light becomes _____ in a colloidal solution.
Question 9 :
The inability among the elderly to see nearby objects clearly because of the weaking of the ciliary muscles is called
Question 10 :
Name the prism required for obtaining the spectrum of infra red radiation<br/>
Question 11 :
At sunrise or sunset, the sun appears to be reddish white. This is because :
Question 12 :
When is the direction of scattered light independent of the wavelength?
Question 13 :
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]