Test on Refraction of light and total internal reflection
Refraction of Light & Total Internal Reflection Explained for Students
Test: Světlo
20 questions
Question 1: The refractive index of a medium is calculated by dividing the speed of light in a vacuum (*c*) by the speed of light in that specific medium (*v*).
A. Yes
B. No
Explanation: The study materials explicitly state: 'The refractive index is defined as the ratio of the speed of light in a vacuum (*c*) to the speed of light in the medium (*v*): *n* = *c* / *v*'.
Question 2: The study materials suggest that in a simulation, the critical angle can only be estimated visually by observing when the refracted ray vanishes, without the possibility of comparing it to a calculated value.
A. Yes
B. No
Explanation: The study materials explicitly state: 'Try to estimate the critical angle by observing when the refracted ray vanishes, and then compare it to the calculated value using the formula sin α_c = n₂ / n₁.' This indicates that the critical angle can be both estimated visually and compared with a calculated value, not only estimated visually.
Question 3: When light passes from an optically denser medium to an optically less dense medium, it always bends towards the normal.
A. Yes
B. No
Explanation: Light bends towards the normal only when passing from an optically less dense medium to an optically denser medium (n₁ < n₂). When light passes from an optically denser medium to an optically less dense medium (n₁ > n₂), it bends away from the normal, as described by Snell's Law where α₂ > α₁.
Question 4: Snell's Law is mathematically expressed as n₁ · cos α₁ = n₂ · cos α₂, where α₁ is the angle of incidence and α₂ is the angle of refraction.
A. Yes
B. No
Explanation: Snell's Law is mathematically expressed as *n₁* · sin α₁ = *n₂* · sin α₂. The formula uses the sine of the angles, not the cosine.
Question 5: When light passes from an optically denser medium to an optically less dense medium, the angle of refraction is greater than the angle of incidence.
A. Yes
B. No
Explanation: If light passes from an optically denser medium (higher n₁) to an optically less dense medium (lower n₂), then n₁ > n₂. For Snell's Law (n₁ · sin α₁ = n₂ · sin α₂) to hold, sin α₂ must be larger than sin α₁, which implies that α₂ > α₁. In this case, the angle of refraction (α₂) is greater than the angle of incidence (α₁), and the light ray bends away from the normal.