If the refractive index of a medium is 1.5, what is the maximum angle of inciden
Practice Questions
Q1
If the refractive index of a medium is 1.5, what is the maximum angle of incidence for total internal reflection when light travels to air?
41.8°
48.6°
60.0°
90.0°
Questions & Step-by-Step Solutions
If the refractive index of a medium is 1.5, what is the maximum angle of incidence for total internal reflection when light travels to air?
Step 1: Understand that the refractive index (n) of a medium tells us how much light bends when it enters that medium. Here, n1 (the medium) is 1.5 and n2 (air) is approximately 1.
Step 2: Recall that total internal reflection occurs when light travels from a denser medium (n1) to a less dense medium (n2).
Step 3: Use the formula for the critical angle (θc), which is sin(θc) = n2/n1.
Step 4: Substitute the values into the formula: sin(θc) = 1/1.5.
Step 5: Calculate 1/1.5, which equals approximately 0.6667.
Step 6: Find the angle whose sine is 0.6667 using a calculator or sine table. This gives θc ≈ 41.8°.
Step 7: Conclude that the maximum angle of incidence for total internal reflection when light travels to air is approximately 41.8°.
Refractive Index – The refractive index is a measure of how much light bends when entering a medium. It is defined as the ratio of the speed of light in a vacuum to the speed of light in the medium.
Total Internal Reflection – Total internal reflection occurs when light attempts to move from a denser medium to a less dense medium at an angle greater than the critical angle, resulting in all the light being reflected back into the denser medium.
Critical Angle – The critical angle is the angle of incidence above which total internal reflection occurs. It can be calculated using the formula sin(θc) = n2/n1, where n1 is the refractive index of the denser medium and n2 is that of the less dense medium.