10 minutes maximum! Can you do it in 5?

1. Which of these diagrams correctly shows the path of a ray of light through a semi-circular plastic block?

2. Which of these statements best describes the path?

" As the ray enters the plastic from the air...

  • A. .. it speeds up and bends away from the normal line".
  • B. .. it speeds up and bends towards the normal line".
  • C. .. it slows down and bends away from the normal line".
  • D. .. it slows down and bends towards the normal line".

3+4: These questions are about refractive index:

3.Which of these formulas states "Snell's Law", used to show the relationship between the angle of incidence (i) and the angle of refraction (r)?

a) n = sin i
sin r

b) n = sin r
sin i

c) r = sin n
sin i

d) i = sin n
sin r

4. What is 'n' in this equation?

  • A. The density of the substance.
  • B. The speed of light in the substance.
  • C. The refractive index of the substance.
  • D. The volume of the substance.

5. The ray of light in question 1 has an angle of incidence of 400 and an angle of refraction of 250.

What is the value of 'n'?

  • A. 1.52
  • B. 0.66
  • C. 0.03
  • D. 1.60

6. Which of the following formulas correctly states the 'critical angle' formula?

a) n = 1

b) sin c = 1

c) sin n = c

d) sin n = 1

7-9: These questions are about total internal reflection in a prism:

7. Which of the following diagrams shows the path of a ray of light that has been totally internally reflected through a glass prism?

8. If the glass prism has a refractive index of 1.6, what is the critical angle of the glass?

  • A. 390
  • B. 420
  • C. 450
  • D. 490

9. The prism shown is a 450 prism, and light is totally internally reflected when it hits the surface at 450.

What is the minimum refractive index for a substance to be used in this prism?

  • A. 1.0
  • B. 1.4
  • C. 1.5
  • D. 1.6
10. Total internal reflection is used in long glass strands to carry light signals. cable line blue optics

These strands are called..

  • A. Light cables.
  • B. Optical fibres.
  • C. Laser channels.
  • D. EM wave cables.