If the angle of incidence is 70° in a medium with a refractive index of 1.6, will total internal reflection occur when it hits air?
Practice Questions
1 question
Q1
If the angle of incidence is 70° in a medium with a refractive index of 1.6, will total internal reflection occur when it hits air?
Yes
No
Only if the angle is less than 90°
Not enough information
Critical angle θc = sin⁻¹(1/1.6) ≈ 38.7°. Since 70° > 38.7°, total internal reflection occurs.
Questions & Step-by-step Solutions
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Q
Q: If the angle of incidence is 70° in a medium with a refractive index of 1.6, will total internal reflection occur when it hits air?
Solution: Critical angle θc = sin⁻¹(1/1.6) ≈ 38.7°. Since 70° > 38.7°, total internal reflection occurs.
Steps: 7
Step 1: Understand the concept of total internal reflection. It occurs when light travels from a denser medium to a less dense medium and the angle of incidence is greater than a certain angle called the critical angle.
Step 2: Identify the refractive index of the first medium (1.6) and the second medium (air, which has a refractive index of approximately 1.0).
Step 3: Calculate the critical angle (θc) using the formula: θc = sin⁻¹(n2/n1), where n1 is the refractive index of the first medium and n2 is the refractive index of the second medium.
Step 4: Substitute the values into the formula: θc = sin⁻¹(1/1.6).
Step 5: Calculate θc, which is approximately 38.7°.
Step 6: Compare the angle of incidence (70°) with the critical angle (38.7°).
Step 7: Since 70° is greater than 38.7°, conclude that total internal reflection will occur.
