Question
The diagram shows a ray of light inside an optical fibre approaching point X.
The light is totally reflected within the fibre.
The refractive index of the material of the optical fibre is 1.39.
Which condition ensures that total internal reflection occurs?
A Q < 45° B Q > 47° C P > 47° D P = Q
Answer/Explanation
Ans:
B
Question
A narrow beam of white light passes through a prism and is dispersed into a spectrum.
Which row is correct?
| colour 1 | colour 2 | colour 3 |
A | blue | yellow | red |
B | red | blue | yellow |
C | red | yellow | blue |
D | yellow | blue | red |
Answer/Explanation
Ans: C
Question
Which statement describes monochromatic light?
A light that does not diffract
B light that has a single frequency
C light that spreads out when shone through a glass prism
D light that travels at the same speed in all materials
Answer/Explanation
Ans: B
Question
Which statement describes monochromatic light?
A light that does not diffract
B light that has a single frequency
C light that spreads out when shone through a glass prism
D light that travels at the same speed in all materials
Answer/Explanation
Ans: B
Question
Very small pollen grains are suspended in water. A bright light shines from the side.
When looked at through a microscope, small specks of light are seen to be moving in a random,
jerky manner.
What are the moving specks of light?
A. pollen grains being hit by other pollen grains
B. pollen grains being hit by water molecules
C. water molecules being hit by other water molecules
D. water molecules being hit by pollen grains
Answer/Explanation
Ans: B