A ray of light in glass (n=1.5) strikes the glass-air interface at an angle of 3
Practice Questions
Q1
A ray of light in glass (n=1.5) strikes the glass-air interface at an angle of 30°. What will be the angle of refraction in air?
60°
30°
45°
90°
Questions & Step-by-Step Solutions
A ray of light in glass (n=1.5) strikes the glass-air interface at an angle of 30°. What will be the angle of refraction in air?
Correct Answer: 60°
Step 1: Identify the refractive indices. The refractive index of glass (n1) is 1.5 and for air (n2) is 1.0.
Step 2: Identify the angle of incidence (θ1). The angle of incidence is given as 30°.
Step 3: Write down Snell's law formula: n1 * sin(θ1) = n2 * sin(θ2).
Step 4: Substitute the known values into the formula: 1.5 * sin(30°) = 1.0 * sin(θ2).
Step 5: Calculate sin(30°). We know that sin(30°) = 0.5.
Step 6: Substitute sin(30°) into the equation: 1.5 * 0.5 = 1.0 * sin(θ2).
Step 7: Simplify the left side: 0.75 = sin(θ2).
Step 8: To find θ2, take the inverse sine (arcsin) of 0.75: θ2 = arcsin(0.75).
Step 9: Calculate θ2, which is approximately 60°.
Refraction and Snell's Law – The question tests the understanding of how light bends when it passes from one medium to another, specifically using Snell's law to calculate the angle of refraction.
