Chhattisgarh State Board Class 6 Science Chapter 12 Light Exercise Multiple Choice, Fill in the Blanks, Questions and Answers here.
Chhattisgarh State Class 6 Science Chapter 12 Solution
(1) Choose the correct option
I.) Time taken by light to travel from the Sun to the Earth is – d) 8 minutes
II.) When moon passes through the middle of the umbra of the earth then – a) Total lunar eclipse occurs
III.) When the sun is at the top of the head , then the length of the shadow of a man will be – b) Minimum
(2) Fill in the blanks –
1.) An object , which has its own light , is called ( source of light ) .
2.) Light travels in a ( straight ) line .
3.) Eclipses of the Moon and the Sun occur due to the shadows cast by the Earth and ( Moon ) respectively .
4.) Change in direction of light rays by a shiny surface is known as ( reflection ) of light .
(3) Short answer questions –
1.) Name any four light sources.
Names of four light sources – The Sun , Torch , Flame of candle , Fire .
3.) Explain the following using ray-diagrams-
(i) Lunar Eclipse (ii) Solar Eclipse
i) Lunar eclipse – On a full-moon night the earth is in between the sun and the moon . Sometimes when these three are in a straight line in the same plane then the moon passes through the umbra made by the earth . In this position , we can not see the part of the moon , that lies in the umbra from any position on the earth . This phenomenon is called the lunar eclipse .
ii) Solar eclipse – On a no moon day , the moon lies in between the earth and the sun . Sometimes , their centres may lie in the same plan on the same straight line . This event occurs only on certain no-moon days , and not on all no-moon days . As the size of the moon is small compared to that of earth , the moon’s shadow falls only on a limited region of the earth . In these regions on the earth , Solar eclipse occurs .
(4) Calculate the time taken by light to travel from the Moon to the Earth, if the distance between them is 4,00,000 kms.
If the distance between the Moon and the Earth is 4,00,000 kms .
Then the time taken by light to travel from the Moon to the Earth is = ( 4,00,ooo / 3,00,000 ) = 4/3 = 1.33 sec
( The speed of light = 3,00,000 km/sec )
(5) Explain by experiment that light travel in a straight line ?
If we light a candle and put one end of the straw in front of the flame of the candle and try to look at the frame from the other side of the straw .
We are able to see the flame . But if we try to see the flame of the candle after bending the straw gently , we can not see the flame . These happen because light moves in a straight line .