Physics

Question 1

1A swimming pool looks shallower than it really is because of

Easy

A. refraction B. reflection C. dispersion D. diffraction

Question 2

2The refractive index of glass in which light travels at 2 × 10⁸ m/s (c = 3 × 10⁸ m/s) is

Easy

A. 0.67 B. 1.5 C. 6 D. 2

Question 3

3Optical fibres carry light by

Easy

A. dispersion B. total internal reflection C. diffraction D. absorption

Question 4

4Light travels at 3 × 10⁸ m/s in air. What is its speed in glass of refractive index 1.5?

Medium

A. 3 × 10⁸ m/s B. 4.5 × 10⁸ m/s C. 2 × 10⁸ m/s D. 1.5 × 10⁸ m/s

Question 5

5The speed of light in water (n = 1.33) is about

Hard

A. 1.33 × 10⁸ m/s B. 3 × 10⁸ m/s C. 4 × 10⁸ m/s D. 2.26 × 10⁸ m/s

Question 6

6Total internal reflection is used in

Easy

A. convex lenses B. plane mirrors C. loudspeakers D. optical fibres

Question 7

7Which colour of light is bent most by a glass prism?

Easy

A. green B. red C. violet D. yellow

Question 8

8Light travels slowest in

Easy

A. glass B. space C. air D. a vacuum

Question 9

9A rainbow is formed by

Easy

A. dispersion and internal reflection of sunlight in raindrops B. diffraction through dust C. reflection off clouds only D. absorption by air

Question 10

10A red shirt looks black under pure blue light because it

Easy

A. gives out red light B. turns the light green C. absorbs the blue light and reflects nothing D. reflects blue light