The change in direction of a wave as it passes from one medium into another where it travels at a different speed.
A straw looks bent in a glass of water because light bends at the surface.
Showing a random 20 of 50 problems.
Example 1
easy
When light refracts into a new medium, which stays the same: frequency or wavelength?
Example 2
challenge
Find the critical angle for total internal reflection at a glass-air boundary, nglass=1.5, nair=1.Find the critical angle θ_c for glass → air
Example 3
hard
Light enters a diamond (n=2.42) from air (n=1.00) at an angle of incidence of 45°. Find the angle of refraction. Then calculate the critical angle for light leaving diamond into air.Air → diamond (n = 2.42): find θ₂
Example 4
medium
Light travels from water (n=1.33) into air (n=1.0) at an angle of incidence of 30°. What is the angle of refraction?Snell's law: find θ₂
Example 5
medium
A medium has light speed v=1.5×108 m/s. Find its refractive index (use c=3×108 m/s).
Example 6
easy
The speed of light in a medium is 2.0×108 m/s. What is the medium's refractive index?
Example 7
medium
Light enters a glass slab (n=1.5) at 60° from the normal. Find the angle inside the glass and verify it leaves the parallel exit face at 60°.
Example 8
challenge
A ray enters a glass slab (n=1.5) from air at θ1=45∘, then exits the parallel far side back into air. What is the exit angle relative to the original direction?
Example 9
easy
Light passes from air (n=1.00) into water (n=1.33) at 45° from the normal. Find the angle of refraction.
Example 10
medium
Light slows from 3×108 m/s in vacuum to 2.4×108 m/s in a plastic. Find the plastic's refractive index.
Example 11
easy
When light goes from a low-index medium to a high-index medium, it bends ___ the normal.
Example 12
medium
Light of wavelength 600 nm in vacuum enters glass with n=1.5. Find its wavelength in the glass.
Example 13
hard
A light ray hits the top of a glass cube (n=1.5) at 40° from the normal. What is the angle the refracted ray makes with the vertical (axis of the cube)?
Example 14
medium
Light goes from medium A (n=1.2) to medium B (n=1.6) at 50° to normal. Find the refraction angle.
Example 15
medium
Light goes from glass (n1=1.5) into air (n2=1) at θ1=30∘. Find sin(θ2).Find sin(θ₂) for glass → air at 30°
Example 16
medium
Find the critical angle for light going from water (n=1.33) into air.
Example 17
easy
A ray normally incident on a flat glass surface refracts at what angle?
Example 18
easy
Why does a straw in a glass of water appear bent?
Example 19
easy
If n1sinθ1=n2sinθ2 and n2>n1, then θ2 is ___ than θ1.
Example 20
medium
Light hits a glass-air interface from the glass side (n=1.5) at 30°. Find the angle of refraction in air.