Unit Test: The Human Eye and The Colourful World | Science Class 10 PDF Download

Time: 1 hour

M.M. 30

Attempt all questions.

• Question numbers 1 to 5 carry 1 mark each.
• Question numbers 6 to 8 carry 2 marks each.
• Question numbers 9 to 11 carry 3 marks each.
• Question number 12 & 13 carry 5 marks each

Q1: Bifocal lenses are used to correct which condition is mentioned below. (1 Mark)
(i) Astigmatism
(ii) Coma
(iii) Myopia
(iv) Presbyopia

Q2: Define the term “accommodation of the eye”. (1 Mark)

Q3:  Which of the following statements about the iris is true? (1 Mark)
(i) It is responsible for producing tears.
(ii) It controls the amount of light that enters the eye.
(iii) It is the outermost layer of the eye.
(iv) It is responsible for detecting color and fine details.

Q4: Which of the following statements about the blind spot in the eye is true? (1 Mark)
(i) It is located in the center of the retina.
(ii) It is the area where the optic nerve exits the eye.
(iii) It is responsible for detecting color and fine details.
(iv) It controls the amount of light that enters the eye.

Q5: The clear sky is blue because (1 Mark)
(i) The atmosphere absorbs the blue light.
(ii) There is the absorption of ultraviolet radiation in the atmosphere.
(iii) There is a scattering of violet and blue light more by the atmosphere when compared to the other colours.
(iv) Light of all other colours is scattered more than the violet and blue light by the atmosphere.

Q6: State the function of each of the following parts of human eye: (2 Marks)
(i) Cornea
(ii) Pupil

Q7:  A lens of power -4.5 D is required by a person to correct his vision. State the defect of vision he is suffering from, calculate the focal length and name the corrective lens. (2 Marks)

Q8: Why is the red light used in the danger signals? (2 Marks)

Q9:

(a) List two causes of hypermetropia.
(b) Draw ray diagrams showing (i) a hypermetropic eye and (ii) its correction using suitable optical device. (3 Marks)

Q10: A person may suffer from both myopia and hypermetropia defects.
(a) What is this condition called?
(b) When does it happen?
(c) Name the type of lens often required by the persons suffering from this defect. Draw labelled diagram of such lenses.(3 Marks)

Q11: Explain hypermetropia. What are the causes and how can they be corrected? (3 Marks)

Q12:  A student is unable to see clearly the words written on the black board placed at a distance of approximately 3 m from him. Name the defect of vision the boy is suffering from. State the possible causes of this defect and explain the method of correcting it. (5 Marks)

Q 13:  What is ‘dispersion of white light’? State its cause. Draw a ray diagram to show the dispersion of white light by a glass prism. (5 Marks)