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Part of the eye which controls the light entering is called 

(a) iris 

(b) cornea 

(c) lens 

(d) retina

 

Answer

Iris controls the amount of light entering the eye by adjusting the size of pupil.

So, (a) is correct

 

We can see a non-luminous object when light: 

(a) emitted by the object falls on the eye. 

(b) is reflected from the object towards our eye. 

(c) completely passes through the object. 

(d) gets completely absorbed by the object

 

Answer

In a non-luminous object, light is reflected from other objects

So, (b) is correct

 

Light is falling on surfaces  S 1   S 2 and  S 3 as shown in the figure.

Surface S1 S2 and S3.png

Surfaces on which the angle of incidence is equal to the angle of reflection is/are

(a) Only S 1    

(b) S 1 and S 2

(c) S 2 and S 3

(d) All the three surfaces

 

Answer

Laws of reflection are always followed, irrespective of the type of surface.

Hence, angle of incidence is equal to angle of reflection in all three cases.

So, (d) is correct

 

Which of the following statements is correct regarding rods and cones in the human eye? 

(a) Cones are sensitive to dim light. 

(b) Cones are sensitive to bright light. 

(c) Rods are sensitive to bright light. 

(d) Rods can sense colour

 

Answer

We know that

  • Cones - They are sensitive to bright light.
  • Rods - They are sensitive to dim light

So, (b) is correct

 

Name the part of the eye which gives colour to the eyes

Answer

Iris is the part of the eye which gives color

 

How many times is a ray of light reflected by two plane mirrors placed parallel and facing each other?

Answer

Since the two mirrors are parallel, 

the ray of light is reflected infinite number of times

 

Which of the following works on the concept of multiple reflections?

  1. Telescope
  2. Binoculars
  3. Kaleidoscope
  4. Sunglasses

 

Answer

Kaleidoscope works on the principle of multiple reflections.

Check the Working of a Kaleidoscope

  1. Class 8
  2. Chapter 16 Class 8 - Light

About the Author

Davneet Singh's photo - Teacher, Computer Engineer, Marketer
Davneet Singh
Davneet Singh is a graduate from Indian Institute of Technology, Kanpur. He has been teaching from the past 9 years. He provides courses for Maths and Science at Teachoo.