Electromagnetic Waves Flashcards
What is a transverse wave
A wave where particle motion is perpendicular to the direction of energy.
What is a wave crest?
The highest point on a transverse wave
What is a wave trough?
The lowest point on a transverse wave
What is the amplitude of the wave?
The vertical distance from the rest position to a crest or to a trough?
How is the wavelength of a transverse wave determined?
It is the horizontal distance from one crest to the next crest.
What is a longitudinal or compression wave?
A wave where the particle motion is parallel to the direction of energy travel.
What is reflection?
Behavior of a wave at a boundary where the incoming wave will bounce back into the original medium.
What is the Law of Reflection?
The angle of the incident wave equals the angle of the reflected wave when measured from the normal.
What is refraction?
When an incident wave enters a new substance at an angle, the transmitted wave will change its speed and bend.
What is diffraction?
The bending of a wave around an obstacle or when it passes through a small opening.
What is the doppler effect?
The apparent change in the frequency of a wave when the source and/or the observer are moving relative to each other.
What type of wave is light?
Light is an electromagnetic wave where photons travel as a transverse wave.
Which parts of the electromagnetic spectrum are considered to be low frequency and long wavelength?
Radio waves, microwaves, and infrared radiation
What is the order of visible light from low frequency to high frequency?
Red, Orange, Yellow, Green, Blue, Indigo and Violet.
Which parts of the electromagnetic spectrum are considered to be high frequency and short wavelength?
Ultraviolet radiation, X-rays, and Gamma radiation
What is the incident wave?
The incoming wave to a boundary.
What is the transmitted wave?
The wave that passes through a boundary into a new medium.
How does light behave in a transparent substance?
Light will transmit through the substance with little distortion.
How does light behave in a translucent substance?
Some of the light is absorbed, while some of the light is distorted that transmits through the substance.
How does light behave in an opaque substance?
The light is absorbed and does not transmit throught he substance.
What is a mirror?
A substance that reflects light with little distortion.
What is the shape of a convex mirror?
A convex mirror curves outward.
What is the shape of a concave mirror?
A concave mirror curves inward.
What are the three shapes of mirrors?
Mirrors can be concave, convex or flat.
What is a lens?
A lens is a curved object that transmits light.
What behavior of waves is used to change the path of an incident wave in a lens?
Refraction
What is the shape of a convex lens?
A convex lens is thicker in the center.
What is the shape of a concave lens?
A concave lens is thicker on the edges.
What happens to parallel rays when they diverge?
They will spread out.
What happens to parallel rays when they converge?
The will bend to meet at a focal point.
What is a prism?
A prism is a substance that will separate white light into its different colors (frequencies).
The color of light represents which characteristic?
Frequency or wavelength
If the three primary colors of transmitted light mix, what is seen?
White light
What are the three primary colors of transmitted light?
Red, Green and Blue
What is a pigment or a dye?
A pigment or dye will absorb some colors of light and reflect other colors.
If a red light is transmitted onto a green pigment, what is seen by an observer?
The observer will see an absence of light. The green pigment will absorb the red light, and no light is reflected to a person’s eyes.
What are the primary colors for pigments and dyes?
Cyan, Magenta and Yellow
What happens to the speed of light when it enters a new substance?
The speed of light will change.
What happens to light waves when an object is beyond the focal point of a concave mirror?
The light rays converge
What happens to light rays from an object in front of a convex mirror?
The light rays diverge, and a virtual image forms.
What happens to parallel light waves that pass through a convex lens?
The light rays will converge at a focal point.
What happens to parallel light rays that pass through a concave lens?
The light rays diverge
What are two uses for radio and TV waves?
Communications and Radar Detection Systems
What are two uses for infrared radiation?
Heat lamps and detecting heat differences (night vision goggles)
What are two uses for ultraviolet rays?
They can help destroy organisms and help skin produce vitamin D
What are two uses for X-rays?
They help to see bones in body and provide pictures inside solid objects
What are two uses for gamma rays?
They can kill cancer cells and be used as an inspection tool.
