CBSE Class 10 Science Chapter-11 Human Eye and Colourful World – Free PDF Download
Free PDF download of Important Questions with Answers for CBSE Class 10 Science Chapter 11 – Human Eye and Colourful World prepared by expert Science teachers from latest edition of CBSE(NCERT) books only by CoolGyan to score more marks in CBSE board examination.
CBSE Class 10 Science Chapter-11 Human Eye and Colourful World Important Questions
CBSE Class 10 science Important Questions Chapter 11 – Human Eye and Colourful World
5 Mark Questions
1. A 14 year old student is not able to see clearly the questions written of the black board placed at a distance of 5 m from him.
(a) Name the defect of vision he is suffering from?
(b) Draw the diagram to show this defect?
(c) Name the type of lens used to correct this defect?
(d) Name two possible cause of this defect.
(e) Draw the diagram to show how this defect can be corrected.
Ans. (a) The student is suffering from myopia.
(b)
(c) Concave lens
(d) (i) Decrease in the focal length of the eye lens
(ii) Eye ball gets elongated.
(e)
2. Make a diagram to show how hypermetropia is corrected. The near point of a hypermetropic eye is 1 m. What is the power of the lens required to correct this defect? Assume that near point of the normal eye is 25 cm.
Ans. Diagram representing the correction of hypermetropia is a follows:
Near point of defective eye is 1 m and that of normal eye is 25 cm.
Here, u = -25 cm, v = -1m = 100 cm.
Using lens formula
1/f = 1/v – 1/u
1/f = 1/-100 + 1/25 = 3/100
f = 100/3 cm = 1/3m.
P = 1/f(m) = 1/0.33 = +3.0 D.