BLOCK 6: NON-IONIZING RADIATION - Unit 2: Electromagnetic (EM) Spectrum (complete)

Question 1

The range of all possible frequencies of electromagnetic radiation.

Answer 1

ELECTROMAGNETIC SPECTRUM

The “electromagnetic spectrum” of an object is the characteristic distribution of electromagnetic radiation emitted or absorbed by that particular object.

Question 2

EMF gets its name from the two fields: electric (E) field and magnetic (H) field. These two fields are pure energy and have _______ mass and charge.

Answer 2

They have NO mass and NO charge. The two fields will be at 90-degree (90°) angles from each other in the far field and will support each other.

Question 3

A vector field, having defined speed and direction, described by the electrical force on a unit charge in space.

Answer 3

ELECTRIC (E) FIELD

Question 4

A vector field describing the force experienced by magnetic objects or moving electrical charges in space.

Answer 4

MAGNETIC (H) FIELD

Question 5

EMF radiation is produced whenever a _______________ carries a current.

Answer 5

CONDUCTOR

Some common sources of EMF radiation are microwave ovens, diathermy, radar, television radio communications, and microwave data link transmission.

Question 6

Four equations that, together, form a complete description of the production and interrelation of electric and magnetic fields.

Answer 6

MAXWELL’S EQUATIONS (MAXWELL-HEAVISIDE EQUATIONS)

When these laws are used to express the fields associated with the conductor, there is an electric and magnetic component, termed the radiated field, which varies inversely with distance from the source.

Question 7

The electric and magnetic fields in the immediate vicinity of an antenna that are non-propagating (do not support each other) and exist in a complex temporal and spatial pattern. These induction fields diminish in strength more rapidly than in inverse proportion to distance.

Answer 7

NEAR FIELD

Question 8

At distances of a few wavelengths, the E and H fields pass through a transitional phase into the _______________, where power density decreases at a predictable rate vs. distance.

Answer 8

FAR FIELD

Question 9

The amount of work that can be performed by a force, an attribute of objects and systems that is subject to a conservation law; the ability to do work.

Answer 9

ENERGY

Question 10

The number of periods or regularly occurring events of any given kind in a unit of time, usually in one second. It is the number of cycles or completed alternations per unit time of a wave or oscillation.

Answer 10

FREQUENCY

Question 11

The distance, measured in the direction of propagation of a wave, between two successive points in the wave that is characterized by the same phase of oscillation. Simply, it is the distance from a point on one cycle to the same point on the next cycle.

Answer 11

WAVELENGTH

Question 12

A physical quantity describing the rate of delivery or transmission of energy.

Answer 12

RADIOFREQUENCY POWER

Question 13

Electromagnetic radiation is emitted in the form of a __________, which has no mass and no charge but is pure energy.

Answer 13

PHOTON

Question 14

Any process in which energy emitted by one body travels through a medium or through space, ultimately to be absorbed by another body.

Answer 14

RADIATION

What makes it radiation is that the energy radiates (i.e., it travels outward in straight lines in all directions) from the source.

Question 15

Any type of radiation that does not carry enough energy to ionize atoms or molecules. Most especially, it refers to the lower energy forms of electromagnetic radiation (i.e. radio waves, microwaves, terahertz radiation, infrared light, and visible light).

Answer 15

NON-IONIZING RADIATION

Question 16

The range of the EM Spectrum primarily used for communication.

Answer 16

RADIOFREQUENCY RANGE (RFR)

Question 17

The frequency range for RFR is _____ kHz to _____ GHz.

Answer 17

3 kHz - 300 GHz

Question 18

Also known as radiant heat, _______________ is found at the lower energy end of the visible spectrum.

Answer 18

INFRARED

Question 19

Found at wavelengths between 400-700 nm. It is received by the eye and is interpreted as color depending on its wavelength.

Answer 19

VISIBLE LIGHT

Question 20

Found above the visible range and bridges the gap between ionizing and non-ionizing radiation.

Answer 20

ULTRAVIOLET LIGHT

Long wave UV is what is typically referred to as “black light”, where short wave UV, which crosses into ionizing radiation, can be used for sanitation and water treatment.

Question 21

Consists of subatomic particles or electromagnetic waves that are energetic enough to remove electrons from otherwise neutral atoms or molecules, ionizing them.

Answer 21

IONIZING RADIATION

Examples of ionizing particles are energetic alpha particles, beta particles, and neutrons.

Question 22

The occurrence of ionization depends on the _______________ of the individual impinging particles or waves, not on their number.

Answer 22

ENERGY

Question 23

Found at the high energy end of the electromagnetic spectrum, these are able to ionize atoms with which they interact.

Answer 23

X-RAY/GAMMA RADIATION

Question 24

Generally, particles or photons with energies __________ only a few electron volts (eV) are ionizing.

Answer 24

ABOVE

Question 25

“Any form of energy can be transformed into another form, but the total energy always remains the same.” refers to which principle?

Answer 25

CONSERVATION OF ENERGY

This principle was first postulated in the early 19th century and applies to any isolated system. Although the total energy of a system does not change with time, its value may depend on the frame of reference. For example, a seated passenger in a moving airplane has zero kinetic energy relative to the airplane but non-zero kinetic energy relative to the earth.