Refraction Of Light Flashcards
What is refraction?
Refraction is the bending of light as it passes from one medium to another due to a change in its speed.
State Snell’s Law.
Snell’s Law is given by n1 sinθ1 = n2 sinθ2, where n is the refractive index and θ is the angle with respect to the normal.
“What is the refractive index?”
It is a measure of how much a material slows down light relative to its speed in a vacuum.
Why does light refract when entering a new medium?
Light refracts because its speed changes when it moves from one medium to another with a different optical density.
Define the critical angle.
The critical angle is the angle of incidence above which total internal reflection occurs, meaning the refracted ray runs along the boundary.
What is total internal reflection?
It is the phenomenon in which light is completely reflected back into a medium when it strikes the boundary at an angle greater than the critical angle.
How does the refractive index vary with wavelength?
Typically, the refractive index decreases as the wavelength increases—a phenomenon known as dispersion.
What is dispersion in optics?
Dispersion is the separation of light into its component colors (wavelengths) due to different refractive indices for different wavelengths.
How do optical fibers use refraction?
Optical fibers guide light by using total internal reflection, keeping the light confined within a core of higher refractive index.
How do lenses use refraction to form images?
Lenses refract light to converge or diverge rays, forming real or virtual images depending on the curvature and arrangement of the lens surfaces.
How does the angle of incidence affect the angle of refraction?
According to Snell’s Law, the angle of refraction depends on the ratio of the refractive indices and the angle of incidence.
In what way do curved surfaces affect refraction?
Curved surfaces focus or disperse light rays, which is critical in the design of optical devices like cameras and telescopes.
