Grade 8 LIGHT REVISION

1) Images formed by a plane mirror is

• always real
• always virtual
• real and virtual
• always inverted

2) The light ray which strikes any surface is called

• Reflected Ray
• Normal
• incident ray
• refracted ray

3) The muscles in the following part contract when right light enters the eye

• Retina
• Cornea
• Pupil
• Iris

4) How many reflected rays can there be for a single incident ray falling on a plane mirror.

• One
• Two
• Infinite
• zero

5) What is the comfortable distance at which one can read with a normal eye?

• 20 cm
• 25 cm
• 30 cm
• 35 cm

6) Cataract is when a person

• cannot see far away objects
• cannot see nearby objects
• cannot see at all
• has foggy vision

7) The deficiency of which vitamin in the diet of a person can leads to night blindness

• vitamin C
• Vitamin D
• Vitamin A
• Vitamin B

8) Night birds have less cones than rods in their eyes.

• True
• False

9) Human eye forms the image of an object at its cornea

• True
• False

10) The size of the pupil of the eye is adjusted by ciliary muscles

• True
• False