Question
What causes the change in direction when light travels from air into glass?
A The amplitude of the light changes.
B The colour of the light changes.
C The frequency of the light changes.
D The speed of the light changes.
Answer/Explanation
Ans: D
Question
Two rays with an angle of incidence of 600 pass into dilute and concentrated sugar-water solutions. The refractions are shown
. Which row is correct?
refractive index as concentration increases | speed through solution as concentration increases | |
A | decreases | decreases |
B | decreases | increases |
C | increases | decreases |
D | increases | increases |
Answer/Explanation
Ans: C
Question
Light travelling at a speed of 3.0 ×108 m/s strikes the surface of a glass block and undergoes refraction as it enters the block.
The diagram shows a ray of this light before and after it enters the block.
What is the speed of light in the glass?
A 1.8 ×108 m/s
B 2.0 ×108 m/s
C 4.5 ×108 m/s
D 5.0 ×108 m/s
Answer/Explanation
Ans: B
Question
Light has a speed of 1.24 × 
m / s in diamond.
What is the refractive index of diamond?
A 0.41
B 1.54
C 2.42
D 3.72
Answer/Explanation
Ans: C
Question
Light passes along an optical fibre.
What happens to the light within the fibre?
A diffraction
B dispersion
C refraction
D total internal reflection
Answer/Explanation
Ans: D