Physics: Reflection, Refraction, Interference, and Nuclear Concepts for Advanced Study

What is reflection?

The bouncing back of light rays when they hit a surface.

What is the Principle of Least Time (Fermat's principle)?

The principle stating that light travels the path that requires the least time.

How to find the point of reflection using the mirror-image trick?

By imagining the light source reflected across the mirror surface to determine the angle of incidence.

What is the Law of Reflection?

The law stating that the angle of incidence (θi) is equal to the angle of reflection (θr).

What are virtual images in plane mirrors?

Images formed by light rays that appear to diverge from a point behind the mirror.

What is the difference between diffuse and specular reflection?

Diffuse reflection scatters light in many directions, while specular reflection reflects light in a single direction.

Why are wet roads harder to see?

Because water creates a reflective surface that can obscure visibility and distort images.

What is refraction?

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

What is the refractive index?

A dimensionless number that describes how fast light travels in a medium compared to a vacuum, defined as n = c / v.

What causes refraction due to temperature layers?

Temperature differences in air can create layers that bend light, resulting in phenomena like mirages.

What are apparent depth illusions?

Visual effects that make objects appear shallower or deeper than they actually are due to refraction.

What is atmospheric refraction?

The bending of light as it passes through the Earth's atmosphere, causing celestial objects to appear higher in the sky.

What causes the twinkling of stars?

The effect of atmospheric turbulence on the light from stars, causing them to appear to change brightness and position.

What is Snell's Law?

A formula that describes how light bends when entering a new medium, defined as n1 sin(θ1) = n2 sin(θ2).

What is total internal reflection?

The complete reflection of light back into a medium when it hits the boundary at an angle greater than the critical angle.

What is the critical angle?

The minimum angle of incidence at which total internal reflection occurs.

What are optical fibers?

Thin strands of glass or plastic that transmit light through total internal reflection for communication purposes.

What causes mirage formation?

Mirages occur when layers of hot air near the ground bend light from the sky, creating the illusion of water.

What is dispersion?

The separation of light into its component colors due to varying refractive indices for different wavelengths.

How do prisms cause dispersion?

Prisms refract different wavelengths of light by different amounts, spreading them into a spectrum.

What causes rainbows?

Rainbows are formed by the dispersion of light in raindrops, resulting in a spectrum of colors in the sky.

Why is the sky blue?

The sky appears blue due to Rayleigh scattering, where shorter blue wavelengths scatter more than other colors.

Why are sunsets red?

Sunsets appear red because the light passes through more atmosphere, scattering shorter wavelengths and allowing longer red wavelengths to dominate.

Why are clouds white?

Clouds appear white because they scatter all wavelengths of visible light equally.

Why does water appear greenish-blue?

Water absorbs longer wavelengths of light (red) and scatters shorter wavelengths (blue), giving it a greenish-blue appearance.