Waves And Radiation

Question 1

What’s the electromagnetic spectrum made up of?

Answer 1

Radio waves, microwaves, infrared, visible , ultraviolet, x-rays, gamma rays

Question 2

Give 3 examples of waves

Answer 2

Water waves
Sound waves
Electromagnetic waves

Question 3

What do waves in the electromagnetic spectrum do?

Answer 3

Transport energy

Question 4

Define a transverse wave

Answer 4

In a transverse wave particles vibrate at 90degrees to direction of travel

Question 5

Name four examples of transverse waves

Answer 5

Water waves, light waves, gamma rays and all members of electromagnetic spectrum

Question 6

Define longitudinal waves

Answer 6

Particles vibrate parallel to the direction the wave travels in

Question 7

Example of a longitudinal wave

Answer 7

Sound

Question 8

How to we work out the speed of a wave?

Answer 8

Dividing the distance it travels by the time it takes to travel that distance

Question 9

Do waves travel at different speeds in different materials?

Answer 9

Yes

Question 10

Define the wavelength of a wave

Answer 10

Horizontal distance between two adjacent crests or troughs

Question 11

Define amplitude

Answer 11

Half the height from top of crest to bottom of a trough

Question 12

Define period of a wave

Answer 12

Time taken for one wave to pass a point

Question 13

What is frequency?

Answer 13

Number of waves per second

Question 14

In reflection what is a normal?

Answer 14

Line drawn at 90degrees to mirror surface

Question 15

Where would you use a curved reflector?

Answer 15

Transmitters , receivers of waves eg sound

Question 16

What is diffraction?

Answer 16

When a wave passes an obstacle it bends around the obstacle

Question 17

Which wavelengths diffract more?

Answer 17

Long

Question 18

If you have a narrow gap does diffraction occur more or less?

Answer 18

More

Question 19

Electromagnetic waves are a combination of what?

Answer 19

Oscillating electric and magnetic waves

Question 20

What is the speed of light?therefore what is the speed of a wave on electromagnetic spectrum?

Answer 20

3x10’8ms-1

Question 21

Which end of the electromagnetic spectrum has a low frequency?

Answer 21

The bottom eg radio waves

Question 22

Which end of the electromagnetic spectrum has the shortest wavelengths?

Answer 22

The top eg gamma rays

Question 23

If an electromagnetic spectrum wave has a higher frequency the greater the..

Answer 23

Amount of energy associated with it eg gamma rays have more energy than radio waves

Question 24

Define refraction

Answer 24

When light changes from one transparent material to another it changes speed

Question 25

What is the speed of light in glass?

Answer 25

2x10’8ms-1

Question 26

What is a critical angle?

Answer 26

When light travels from glass to air and the angle of refraction is 90degrees, then the angle of incidence in the glass is called the critical angle

Question 27

Name 3 ways in which radiation can be detected

Answer 27

It blackens photographic film, passes through a Geiger muller tube and radiation causes scintillations

Question 28

Name four natural and man made sources which background radiation come from

Answer 28

Radon gases from rocks and soil
Gamma rays from the ground
Carbon and potatpssium in the body
Cosmic rays

Question 29

Name three examples of exposure to man made radiation sources

Answer 29

Medical X-rays
Airplane flights
Nuclear industry

Question 30

Define half life

Answer 30

The half life of a radio active source is the time it takes half of the unstable nuclei in the source to decay. Half life is also the time it takes for the activity of a source to fall by half

Question 31

What are the four steps for measuring the half life of a radiative source?

Answer 31

1. Measure background count rate
2. Direct source at Geiger muller tube and measure the count rate at regular intervals
3. Subtract background count rate from count rate
4. Draw a graph of corrected count rate vs time

Question 32

What are the three types of radiation

Answer 32

Alpha, beta, gamma

Question 33

What are three ways to reduce exposure to radiation?

Answer 33

Shielding i.e. Lead aprons, distance and exposure i.e. Keep time exposed to a minimum

Question 34

Give an advantage of nuclear power

Answer 34

Do not release co2

Question 35

Give a disadvantage of nuclear power

Answer 35

Waste from reactions is radioactive which makes it problematic to store

Question 36

Give 5 examples of using radiation

Answer 36

Radiotherapy, instrument sterilization, traders, industry, agriculture

Question 37

What is nuclear fission.

Answer 37

A large nucleus is made to split into two smaller nuclei with the release of a number of neutrons energy

Question 38

What is nuclear fusion?

Answer 38

Occurs when two small nuclei join together to make a larger nucleus. During this fusion reaction energy is released. Stars use a fusion reaction to release energy

Question 39

What’s alpha particle?

Answer 39

Made of 2 protons and 2 neutrons

Question 40

What’s beta particle

Answer 40

Very fast moving electron. For,Ed when a neutron in the nucleus changes into a proton and a electron

Question 41

What’s gamma radiation?

Answer 41

High frequency, high energy, electromagnetic radiation. Moves at the speed of light

Question 42

What’s radiactivity?

Answer 42

Process ny which an unstable nucleus attempts to become stable by emoting radiation.

Question 43

Which type of radiation is the most and least penetrating?

Answer 43

A is least. Y is most