If the angle of incidence is 70° in glass (n=1.5), will total internal reflection occur when light travels to air?
Practice Questions
1 question
Q1
If the angle of incidence is 70° in glass (n=1.5), will total internal reflection occur when light travels to air?
Yes
No
Only if the angle of refraction is 30°
Only if the angle of refraction is 45°
The critical angle for glass to air is sin⁻¹(1/1.5) ≈ 41.8°. Since 70° > 41.8°, total internal reflection will occur.
Questions & Step-by-step Solutions
1 item
Q
Q: If the angle of incidence is 70° in glass (n=1.5), will total internal reflection occur when light travels to air?
Solution: The critical angle for glass to air is sin⁻¹(1/1.5) ≈ 41.8°. Since 70° > 41.8°, total internal reflection will occur.
Steps: 7
Step 1: Understand the concept of total internal reflection. It occurs when light travels from a denser medium (like glass) to a less dense medium (like air) and the angle of incidence is greater than a certain critical angle.
Step 2: Identify the refractive index of glass, which is given as n = 1.5.
Step 3: Calculate the critical angle using the formula: critical angle = sin⁻¹(1/n). Here, n is the refractive index of glass.
Step 4: Substitute the value of n into the formula: critical angle = sin⁻¹(1/1.5).
Step 5: Calculate the critical angle: critical angle ≈ 41.8°.
Step 6: Compare the angle of incidence (70°) with the critical angle (41.8°).
Step 7: Since 70° is greater than 41.8°, conclude that total internal reflection will occur.
