MEDIUM
10th CBSE
IMPORTANT
Earn 100

The iris is a muscular diaphragm that controls the size of the pupil. It consists of two layers: the front pigmented fibrovascular layer known as a stroma and, beneath the stroma, pigmented epithelial cells. The colour of the eye is defined by the pigmentation of the iris.

Question Image
Which of the following can be directly affected if the iris does not function properly?

44.44% studentsanswered this correctly

Important Questions on The Human Eye and the Colourful World

MEDIUM
10th CBSE
IMPORTANT
Rohan lit an incense stick in his room and after an hour observed that when a beam of sunlight entered his room through a small gap in the window, he was able to see the path of the beam. Which of the following is most likely TRUE about the air present in the room?
MEDIUM
10th CBSE
IMPORTANT
In a medium like glass, the velocity of light increases as the wavelength increases. Which of the following light would be the fastest in glass?
MEDIUM
10th CBSE
IMPORTANT
Which of the following correctly gives the sequence of events that take place when human eye changes its focus from a distant object to an object closer to the eye?
MEDIUM
10th CBSE
IMPORTANT
A person's near point is at 45 cm and far point is at 2 m. What kind of corrective lens is BEST suited for his vision defect?
MEDIUM
10th CBSE
IMPORTANT

Nanda saw rays of sunlight entering into a dark room as shown below. He then did something to the air in the room after which he was NOT able to see the rays of sunlight in the room. What is it that Nanda could have done to make the rays of sunlight invisible? Justify your answer.

Question Image

 

MEDIUM
10th CBSE
IMPORTANT

Mars's atmosphere is composed mainly of carbon dioxide, nitrogen and argon and negligible amounts of oxygen, water vapour and methane.

Using the information given in the sentence above and knowledge about how rainbows are formed on Earth, explain why rainbow formation is impossible on Mars.

MEDIUM
10th CBSE
IMPORTANT
Space is mostly vacuum, devoid of any medium. What colour does the Sun appear to the astronauts on International Space Station? Give reasons for your answer.
HARD
10th CBSE
IMPORTANT
Hypermetropia and myopia are the most common defects of vision affecting humans. Both these defects can be corrected and perfect vision can be restored with the use of suitable lenses of appropriate focal lengths. Hypermetropia can be corrected by using convex lenses while myopia can be corrected by using concave lenses. The power of prescribed lens for both these defects depends on the focal length of the respective corrective lens. The power, P of the lens is given by
P=1f(in metres) dioptres
Now, consider a situation in which the near point of a defective eye is at a distance of 1.0 m. Assuming the near point of a normal eye to be 25 cm, answer the following question:
If one wishes to reduce the near point of this eye to 0.5 m by using a lens, what will be its power?