Fill in the blanks in the following :

(a) A person 1 m in front of a plane mirror seems to be _______________ m from his image.

Answer

2

Explanation

Distance of the person from mirror is same as the distance of his image from the mirror

Thus,

If a person is 1 m away from the mirror, his image will also be 1m from the mirror

Thus, the image will be 1+1 m (= 2 m) away from the person

(b) If you touch your ____________ ear with right hand in front of a plane mirror it will be seen in the mirror that your right ear is touched with____________

Answer

Left hand

Explanation

This is because of the lateral inversion of the image

(c) The size of the pupil becomes ____________ when you see in dim light.

Answer

Large

Explanation

In dim light,the light which enters our eye is very little,so to increase the amount of light,the size of pupil increases

(d) Night birds have ____________ cones than rods in their eyes..

Answer

Less

Explanation

Rods helps in vision during the dim light and cones help vision in normal or bright light

Since Night birds can see in the night and not in the day,

Therefore, they have more rod cells.

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

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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.