Answer:
Frequency
Explanation:
The frequency ( ) of a wave is the number of waves passing a point in a certain time.
Answer:
The correct option is;
Still constant
Explanation:
The relative refractive index ₁n₂ between the two medium can be as follows;

Therefore, given that the speed of light in medium 1 is constant and the speed of light on medium 2 is also constant, the relative refractive index ₁n₂ = c₁/c₂ is always constant.