Question

Q. What part of second is called nanosecond?

One hundredth

One billionth

One millionth

One Thousandth



Q. _________ is the phenomenon by which incident ray of light is sent back to same medium after falling on a smooth surface.
(A) Refraction
(C) Dispersion
(B)Reflection
(D) Alomization​
Q. _____image is formed by a pinhole camera.

Irregular

Erected

Inverted

None of these

Q. Read the statements and choose the correct option.
1. Moon is a luminous sources of light.
2. A glow worm is a natural source of light.

A. only i is true
B. only ii is true
C. Both are true
D. Both are false

Answer 1

1). Billionth

2). Reflection

3). Inverted

4). Only ii is true

Answer 2

(i) A nanosecond (ns or nsec) is one billionth (10 -9 ) of a second.

(ii)  reflection

(iii) Inverted

(iv) B. only ii is true