EM WAVES

Question 1

He had proved that light was an electromagnetic wave

Answer 1

James Clerk Maxwell

Question 2

In _____ Maxwell wrote down an equation to describe these electromagnetic waves

Answer 2

1865

Question 3

He noticed that electrical fields and magnetic fields can couple together to form electromagnetic waves

Answer 3

James Clerk Maxwell

Question 4

He demonstrated the generation and detection of radio waves in 1887, eight years after Maxwell’s death.

Answer 4

Heinrich Hertz

Question 5

He also showed that these waves travel at the speed of light (as predicted by Maxwell).

Answer 5

Heinrich Hertz

Question 6

Types of Electromagnetic Radiation (lowest to highest EM spectrum)

Answer 6

RADIOWAVES > MICROWAVES > INFRARED RADIATION > VISIBLE LIGHT > ULTRAVIOLET > XRAYS > GAMMA RAYS

Question 7

The terms ____, _______ and ______ all refer to the same physical phenomenon: Electromagnetic energy

Answer 7

Light, electromagnetic waves and radiation

Question 8

The terms light, electromagnetic waves and radiation, all refer to the same physical phenomenon: ?

Answer 8

Electromagnetic energy

Question 9

the no. of crests that pass a given point within 1 second. Measured in Hertz (Hz); radio waves and microwaves

Answer 9

Frequency

Question 10

the distance between the crests. Measured in wavelength (meters); infrared rays and visible light

Answer 10

Wavelength

Question 11

Measured in electron Volts (eV). An electron volt is the amount of kinetic energy needed to move an electron through one-volt potential ; x-rays and gamma rays

Answer 11

Energy

Question 12

Properties of Electromagnetic Wave

Answer 12

1. Transverse wave
2. Light is an Electromagnetic wave
3. Can travel through a vacuum
4. Electromagnetic waves carry energy and momentum
5. . They obey the equation c = fλ

Question 13

What is f and λ

Answer 13

f is frequency in Hertz and λ is wavelength meters

Question 14

Are at the lowest range of the EM spectrum.

Answer 14

Radio Waves

Question 15

used primarily for communications including voice, data, and entertainment media.

Answer 15

Radio

Question 16

fall in the range of the EM spectrum between radio and IR.

Answer 16

Microwaves

Question 17

used for high-bandwidth communications, radar, and as a heat source for microwave ovens and industrial applications

Answer 17

Microwaves

Question 18

in the range of the EM spectrum between microwaves and visible light.

Answer 18

Infrared

Question 19

Is invisible to human eyes, but we can feel it as heat if the intensity is sufficient.
Commonly used as heat sensors

Answer 19

IR Light

Question 20

is found in the middle of the EM spectrum, between IR and UV.
defined as the wavelengths that are visible to most human eyes..

Answer 20

Visible Light

Question 21

is a component of sunlight; however, it is invisible to the human eye. It has numerous medical and industrial applications, but it can damage living tissue.

Answer 21

Ultraviolet / UV Light

Question 22

comprise the range of the EM spectrum between UV and gamma rays

Answer 22

Soft X-rays

Question 23

occupy the same region of the EM spectrum as gamma rays.

Answer 23

Hard x-rays

Question 24

X-rays are produced by?

Answer 24

Accelerating electrons

Question 25

gamma rays are produced by ?

Answer 25

Atomic nuclei

Question 26

Causes damage to living tissue, which makes it useful for killing cancer cells when applied in carefully measured doses to small regions. Uncontrolled exposure, though, is extremely dangerous to humans

Answer 26

Gamma rays

Question 27

a measure of the bending of a ray of light when passing from one medium into another

Answer 27

Index of Refraction

Question 28

a branch of physics that deals with the determination of behavior and the properties of light, along with its interactions with matter and also with the instruments which are used to detect it.

Answer 28

Optics

Question 29

Defined as the bouncing back of light

Answer 29

Reflection

Question 30

If the surface is smooth and shiny, like glass, water, or polished metal the light will reflect at the same angle as it hit the surface. This is called ?

Answer 30

Specular Reflection

Question 31

states that when a ray of light reflects off a surface, the angle of incidence is equal to the angle of reflection.

Answer 31

Law of Reflection

Question 32

The image formed by the plane mirror is always _____, _____ and ____ as the object is reflecting,

Answer 32

virtual, upright and same shape and size

Question 33

It states that incident ray, the refracted ray and the normal to the interface, all lie in the same plane.

Answer 33

Law of Refraction or Snell's Law

Question 34

is the bending of light (it also happens with sound, water, and other waves) as it passes from one transparent substance into another.

Answer 34

Refraction

Question 35

When light travels from air into water, it ______, causing it to change direction slightly

Answer 35

slows down

Question 36

If light travels go through a substance with a lower refractive index (such as from water into the air) it_______. The light bends AWAY from the normal line.

Answer 36

speeds up

Question 37

When light enters a denser substance (higher refractive index), it ‘bends’ more _______ the normal line.

Answer 37

TOWARDS