8.03 Reflection & Refraction Practice Quiz

The law of reflection states that the angle at which light strikes a surface is equal to the angle at which it reflects off that surface. This fundamental principle underlies the behavior of light in mirrors and smooth surfaces.

A smooth, polished surface allows light rays to reflect in a uniform direction, thereby producing a clear image. In contrast, rough surfaces scatter light in multiple directions, leading to a blurred reflection.

The index of refraction is defined as n = c/v, where c is the speed of light in a vacuum and v is its speed in the medium. It quantifies how much the light slows down in the medium compared to the vacuum.

Refraction is the bending of light as it passes from one medium into another due to a change in its speed. This principle is encapsulated in Snell's Law.

Total internal reflection occurs when light traveling within a denser medium hits the boundary with a less dense medium at an angle greater than the critical angle. Under these circumstances, all the light is reflected back into the medium, with none transmitted.

By applying Snell's Law, we find sin θ₂ = (1.00/1.33) � - sin 30°, which gives sin θ₂ ≈ 0.376. Taking the inverse sine yields an angle of approximately 22°, demonstrating how light bends when entering water from air.

Refraction causes light rays to bend when passing from water to air, leading to a displacement between the actual and the perceived position of underwater objects. This optical illusion makes objects appear closer to the surface.

Concave mirrors converge light rays and can form real, inverted images when the object is placed at certain distances. Convex mirrors, however, always form virtual, upright, and reduced images due to their diverging nature.

Lenses work by refracting light - that is, bending light rays as they pass through the lens. This property allows lenses to either converge or diverge light to form clear images in devices such as cameras, microscopes, and telescopes.

By applying the thin lens equation (1/f = 1/d�' + 1/dᵢ), substituting f = 10 cm and d�' = 20 cm yields an image distance (dᵢ) of 20 cm. This confirms that the image appears on the opposite side of the lens at 20 cm from it.

Convex mirrors are designed to curve outward, which causes them to capture a wider field of view compared to flat or concave mirrors. This makes them ideal for applications like car side-view mirrors.

The critical angle is the threshold incidence angle above which total internal reflection takes place. It is the minimum angle at which all light is reflected back into the medium when transitioning from a denser to a rarer medium.

Light travels faster in a less dense medium because the optical density is lower. This results in an increase in speed when light moves from a denser medium to a rarer one.

Eyeglasses consist of lenses that refract incoming light to adjust the focal point on the retina, thereby correcting vision. This application of refraction is essential in compensating for refractive errors such as myopia or hyperopia.

Dispersion occurs because different wavelengths of light refract at slightly different angles as they pass through a medium. This phenomenon separates white light into a spectrum of colors, as observed in prisms.

When light travels from a medium with a higher refractive index (glass) to a lower one (water), it speeds up and bends away from the normal. This behavior is well explained by Snell's Law.

For a concave mirror, when an object is placed beyond the center of curvature, the image is real, inverted, and reduced. As the object moves closer (but still outside the focal point), the image becomes magnified while still remaining real and inverted.

The optical power of a lens is defined as the reciprocal of its focal length (P = 1/f). This inverse relationship means that as the focal length decreases, the optical power increases.

According to the law of reflection, the angle of reflection is equal to the angle of incidence. Therefore, with an incidence angle of 50°, the reflection angle is also 50°.

The splitting of white light into a spectrum of colors occurs because different wavelengths are bent by different amounts as they pass through the prism - a phenomenon known as dispersion. This causes each color to emerge at a slightly different angle.