MCAT Physics Ch. 8 Light & Optics

Transverse waves that consist of oscillating electric field & oscillating magnetic field that are perpendicular to each other & to the direction of propagation of the wave

The range of frequencies & wavelengths found in EM waves. From lowest to highest energy:

1. Radio waves
2. Microwaves
3. Infrared
4. Visible Light
5. Ultraviolet
6. X-rays
7. γ-rays

400nm (violet) - 700nm (red)

The rebounding of incident light waves at the boundary of a medium

The incident angle will equal the angle of reflection, as measured from the normal

Have centers (C) & radii of curvature (r), as well as focal points (F)

• Concave Mirrors - are converging systems, & produce real, inverted images, or virtual upright images, depending on the placement of the object relative to the focal point

• Convex Mirrors - are diverging, & will only produce virtual, upright images

Produce virtual, upright images; these images are always the same size as the object. They may be thought of as spherical mirrors w/ infinite radii of curvature (these are the mirrors that we look into)

Bending of light as it passes from one medium to another. The speed of light changes depending on index of refraction of the medium, & this speed change causes refraction

The amount of refraction depends on the wavelength of the light involved; this behavior causes dispersion of light thru a prism (different wavelengths get refracted at a different angle)

There is an inverse relationship between the index of refraction & the sine of the angle of refraction (measured from the normal)

A dimensionless quantity of a medium. How much light is refracted in a specific medium. For a vacuum, it is 1, & all other substances are greater than 1. For air, it is essentially 1.

Occurs when light cannot be refracted out of a medium & is instead reflected back inside the medium (occurs at any angle of incidence greater than the critical angle)

• Happens when light moves from a medium w/ a higher index of refraction to a medium w/ lower index of refraction, so the refracted angle will be higher than the incident angle (the refracted ray bends away from the normal)
• The minimum incident angle at which total internal reflection occurs is called the critical angle at which the refracted light ray passes along the interface of the 2 media

Refract light to form images of objects

• Thin symmetrical lenses have focal points on each side
• (Normally on the MCAT they will have negligible thickness, but if not, you must use Lensmaker's equation)

• Convex Lens - converging systems & can produce real, inverted images or virtual, upright images

• Concave Lens - diverging systems & will only produce virtual, upright images