Flash Cards: Light – Reflection and Refraction

Reflection is the bouncing back of light rays when they strike a surface.

The law of reflection states that the angle of incidence is equal to the angle of reflection.

A real image can be projected on a screen, while a virtual image cannot be projected and is formed by the apparent intersection of rays.

Refraction is the bending of light as it passes from one medium to another due to a change in speed.

Refractive index is the ratio of the speed of light in a vacuum to the speed of light in a medium.

Snell's Law states that n1 * sin(θ1) = n2 * sin(θ2) where n is the refractive index and θ is the angle.

Total internal reflection occurs when a light ray hits the boundary at an angle greater than the critical angle, causing it to reflect entirely within the medium.

Reflection is used in mirrors for personal grooming, in periscopes, and in telescopes.

Refraction is used in lenses to correct vision and in optical instruments like cameras.

A concave mirror can form real, inverted images if the object is outside the focal point.

A convex mirror always forms virtual, erect, and diminished images.

The critical angle is the angle of incidence at which total internal reflection occurs.

Optical fibers use total internal reflection to transmit light signals over long distances.

The speed of light changes with different wavelengths, affecting how light refracts in different mediums.

Ray diagrams help visualize the path of light and determine image characteristics in mirrors and lenses.

Students often confuse virtual images with real images; always remember that virtual images cannot be projected.

Light bends when it enters a different medium at an angle due to a change in its speed.

Color dispersion is the separation of light into its component colors due to refraction in a prism.