Waves and Radiation

Question 1

What is a Wave?

Answer 1

A wave is a term used to describe how energy is transferred from one point to another

Question 2

What is wavelength?

Answer 2

Wavelength is the length of one full wave

Question 3

What is the frequency of a wave?

Answer 3

The frequency is the number of waves that pass a point in one second

Question 4

What is the amplitude of a wave?

Answer 4

The amplitude of a wave is the distance from the rest point to a crest or trough

Question 5

What is the period of a wave?

Answer 5

The period of a wave is the time it takes to complete one full cycle

Question 6

What are the two types of waves called?

Answer 6

Transverse and longitudinal

Question 7

Describe a transverse wave?

Answer 7

In a transverse wave the vibrations occur perpendicular to the direction of the wave.

Question 8

Describe a longitudinal wave?

Answer 8

In a longitudinal wave the particles vibrate in the same direction as the wave is travelling

Question 9

What is the speed of all electromagnetic radiations?

Answer 9

3 X 8 10^8m/s

Question 10

What are the four properties that identify waves?

Answer 10

Reflection, Refraction, Interference and diffraction

Question 11

When does reflection occur?

Answer 11

Reflection occurs when a wave strikes a barrier and is reflected off that barrier.

Question 12

When does refraction occur?

Answer 12

Refraction occurs when a wave changes speed as it moves from one medium to another?

Question 13

When does interference occurs?

Answer 13

Interference occurs when two or more waves combine

Question 14

Explain diffraction?

Answer 14

When waves pass by a barrier or by an edge or through a gap they spread or bend behind the barrier this is know as diffraction.

Question 15

What are the parts of the electromagnetic spectrum?

Answer 15

Radio waves, Microwaves, Infrared, Visible light, Ultraviolet, X-rays, Gamma rays

Question 16

What part of the electromagnetic spectrum has the longest wavelength?

Answer 16

Radio waves

Question 17

What part of the electromagnetic spectrum has the greatest frequency?

Answer 17

Gamma rays

Question 18

What is known as the normal?

Answer 18

The normal is an imaginary line drawn perpendicular to the boundary between the two materials

Question 19

What is known as the angle of incidence?

Answer 19

The angle of incidence is the angle between the incident ray and the normal

Question 20

what is known as the angle of refraction?

Answer 20

The angle of refraction is the angle between the refracted ray and the normal

Question 21

What is the definition of refraction in terms of light?

Answer 21

Refraction is that the light changes speed when moving from one medium to another

Question 22

What are the two main types of lenses called?

Answer 22

Converging and diverging

Question 23

Describe an atom?

Answer 23

An atom has a nucleus that is composed of neutrons and protons. the electrons orbit the nucleus

Question 24

What are the 3 types of radiation?

Answer 24

Alpha radiation, Beta Radiation and gamma radiation

Question 25

Describe an alpha particle?

Answer 25

An alpha particle is a large particle composed of two protons and two neutrons. Has an overall charge of +2

Question 26

Describe a Beta particle?

Answer 26

A beta particle is an electron | Has a charge of -1

Question 27

Describe Gamma radiation?

Answer 27

Gamma radiation is a high energy photon emitted from an excited or energetic atom no charge and no mass

Question 28

How can alpha radiation be stopped?

Answer 28

a sheet of paper or being a distance of 20cm away in air

Question 29

How can beta radiation be stopped?

Answer 29

Thin sheet of aluminium

Question 30

How can Gamma radiation be stopped?

Answer 30

Lead or concrete ae required

Question 31

What is background radiation made up of?

Answer 31

Natural and artificial sources

Question 32

Name four natural sources of radiation and explain?

Answer 32

Cosmic rays - Radiation from space Animals - Animals emit natural levels of radiation Rocks - Some give off radioactive radon gas Soil and plants - Radioactive materials from rocks in the ground absorbed by soil hence passed to plants

Question 33

What is absorbed dose?

Answer 33

Absorbed dose is the energy absorbed from a radioactive material divided by the mass of the material receiving the dose?

Question 34

What is Equivalent dose?

Answer 34

Equivalent dose is the absorbed dose multiplied by the radiation weighting factor

Question 35

What are some of the uses of nuclear radiation?

Answer 35

``` Diagnosis - X-Ray, Tracers Radiography Tracers Sterilisation Carbon Dating ```

Question 36

What is meant by the term half life?

Answer 36

the half life of a radioactive source is the time for the activity to fall to half its original value?

Question 37

What is meant by the term Activity?

Answer 37

Activity of a radioactive source is the number of nuclei decaying per second

Question 38

Explain briefly how a nuclear power stations work?

Answer 38

Radioactive materials used to generate large amounts of heat This heat is used to turn water into steam Steam drives turbines to generate electrical energy

Question 39

What are the two main types of nuclear reactions?

Answer 39

Fission and fusion

Question 40

What is fission?

Answer 40

Fission is the process in which one nucleus splits into more than one nuclei which releases energy

Question 41

What is fusion

Answer 41

Fusion is the combing of nuclei of light elements to give heavier nuclei.