Page 63 - Science Class 6 Times Publication

by reecting the light of others are called non-luminous bodies.
4. The substances through which light can pass easily are called
transparent substances.

5. The substances through which light passes partially are called
translucent substances.
6. The substances through which light does not pass at all are
called opaque substances.
7. The phenomenon in which light travels in a straight line
through a same transparent medium is called rectilinear
propagation of light.

Exercise

1. Choose the best alternative in each case:
a. What time is taken by the sunlight to reach the earth?

i. 5 min ii. 6 min 30 sec
8
iii. 8 min 20 sec iv. 3 x 10 sec
b. The tail of a  rey glows at night due to a chemical substance

called

i. Lime ii. Luciferin
iii. Lantern iv. Limestone

c. Which of the following is a non-luminous object?

i. Sun ii. Stars
iii. Fire iv. Moon

d. Which of the following is a translucent substance?

i. Glass ii. Water
iii. Air iv. None of these

e. Plastic is
i. Transparent ii. Translucent
iii. Opaque iv. None of these

Times' Crucial Science and Environment 59 Book 6