Vocab #8

Question 1

Decibel

Answer 1

a dimensionless unit that describes the ratio of two intensities of sound; the threshold of hearing is commonly used as the reference intensity.

Question 2

Pitch

Answer 2

a measure of how high or low a sound is perceived to be, depending on the frequency of the sound wave.

Question 3

Harmonic Series

Answer 3

a series of frequencies that includes the fundamental frequency and integral multiples of the fundamental frequency.

Question 4

Polarization

Answer 4

property of certain electromagnetic radiations in which the direction and magnitude of the vibrating electric field are related in a specified way.

Question 5

Diffraction

Answer 5

a change in the direction of a wave when the wave encounters an obstacle, an opening or edge.

Question 6

Angle of Incidence

Answer 6

the angle between a ray that strikes a surface and the line perpendicular to that surface at the point of contact.

Question 7

Angle of Reflection

Answer 7

the angle formed by the line perpendicular to a surface and the direction in which a reflected ray moves.

Question 8

Red Shift

Answer 8

the wavelength of the light is stretched, so the light is seen as ‘shifted’ towards the red part of the spectrum.

Question 9

Blue Shift

Answer 9

is any decrease in wavelength (increase in energy), with a corresponding increase in frequency, of an electromagnetic; the opposite effect is referred to as redshift.

Question 10

Spectroscopes

Answer 10

an optical device for producing and observing a spectrum of light or radiation from any source, consisting essentially of a slit through which the radiation passes, a collimating lens, and an amici prism.

Question 11

Convex Lens/Mirror

Answer 11

a mirror whose reflecting surface is an outward-curved segment of a sphere.

Question 12

Concave Lens/Mirror

Answer 12

a mirror whose reflecting surface is an inward-curved segment of a sphere.

Question 13

Virtual Image

Answer 13

an image from which light rays appear to diverge, even though they are not actually focused there; a virtual image cannot be projected on a screen.

Question 14

Real Image

Answer 14

an image that is formed by the intersection of light rays; a real image can be projected on a screen.

Question 15

Erect Image

Answer 15

is formed when both rays intersect each other at a certain point; image appears right side up.

Question 16

Focal Length

Answer 16

is the distance between the center of a convex lens or concave mirror and the focal point of the lens or mirror - the point where parallel rays of light meet, or converge.

Question 17

Focal Point

Answer 17

is the point in space where parallel light rays meet after passing through the lens or bouncing off the mirror.