A light ray in glass (n=1.5) strikes the boundary with air at an angle of 30°. W
Practice Questions
Q1
A light ray in glass (n=1.5) strikes the boundary with air at an angle of 30°. Will it undergo total internal reflection?
Yes
No
Depends on the angle
Not enough information
Questions & Step-by-Step Solutions
A light ray in glass (n=1.5) strikes the boundary with air at an angle of 30°. Will it undergo total internal reflection?
Step 1: Identify the refractive index of glass, which is n = 1.5.
Step 2: Identify the refractive index of air, which is approximately n = 1.0.
Step 3: Calculate the critical angle (θc) using the formula θc = sin⁻¹(n2/n1), where n1 is the refractive index of glass and n2 is the refractive index of air.
Step 4: Substitute the values into the formula: θc = sin⁻¹(1.0/1.5).
Step 5: Calculate θc, which is approximately 41.8°.
Step 6: Compare the angle of incidence (30°) with the critical angle (41.8°).
Step 7: Since 30° is less than 41.8°, the light ray will not undergo total internal reflection.
Refraction and Total Internal Reflection – Understanding the conditions for total internal reflection, including the critical angle and the relationship between the indices of refraction of two media.
