If the critical angle for a certain material is 30°, what is the refractive inde
Practice Questions
Q1
If the critical angle for a certain material is 30°, what is the refractive index of that material?
1.00
1.15
1.73
2.00
Questions & Step-by-Step Solutions
If the critical angle for a certain material is 30°, what is the refractive index of that material?
Correct Answer: 2.00
Step 1: Understand that the critical angle (θc) is the angle of incidence above which total internal reflection occurs.
Step 2: Know the formula to find the refractive index (n) using the critical angle: n = 1/sin(θc).
Step 3: Identify the given critical angle, which is 30°.
Step 4: Calculate sin(30°). The value of sin(30°) is 0.5.
Step 5: Substitute the value of sin(30°) into the formula: n = 1/sin(30°) = 1/0.5.
Step 6: Perform the division: 1 divided by 0.5 equals 2.00.
Step 7: Conclude that the refractive index of the material is 2.00.
Critical Angle and Refractive Index – The critical angle is the angle of incidence above which total internal reflection occurs, and it is related to the refractive index of a material through the formula n = 1/sin(θc).
