A ray of light passes from air into glass at an angle of incidence of 45 degrees
Practice Questions
Q1
A ray of light passes from air into glass at an angle of incidence of 45 degrees. If the refractive index of glass is 1.5, what is the angle of refraction?
30 degrees
45 degrees
60 degrees
90 degrees
Questions & Step-by-Step Solutions
A ray of light passes from air into glass at an angle of incidence of 45 degrees. If the refractive index of glass is 1.5, what is the angle of refraction?
Step 1: Identify the refractive indices. The refractive index of air (n1) is approximately 1, and the refractive index of glass (n2) is 1.5.
Step 2: Identify the angle of incidence (i). In this case, the angle of incidence is given as 45 degrees.
Step 3: Write down Snell's law formula: n1 * sin(i) = n2 * sin(r).
Step 4: Substitute the known values into the formula: 1 * sin(45 degrees) = 1.5 * sin(r).
Step 5: Calculate sin(45 degrees). This is equal to √2/2 or approximately 0.707.
Step 6: Substitute this value into the equation: 1 * 0.707 = 1.5 * sin(r).
Step 7: Rearrange the equation to solve for sin(r): sin(r) = 0.707 / 1.5.
Step 8: Calculate sin(r): sin(r) ≈ 0.4713.
Step 9: Use the inverse sine function to find r: r = sin^(-1)(0.4713).
Step 10: Calculate the angle r, which is approximately 30 degrees.
Refraction – The bending of light as it passes from one medium to another due to a change in speed.
Snell's Law – A formula used to describe the relationship between the angles of incidence and refraction when light passes between two different media.
Refractive Index – A dimensionless number that describes how fast light travels in a medium compared to vacuum.
