P2 - Radiation and Life

Question 1

Name the types of electromagnetic wave from lowest energy/ frequency to highest

Answer 1

Radio Waves, Micro-Waves, Infrared, Visible Light, Ultra-Violet, X-rays, Gamma Rays

Question 2

Photons

Answer 2

Packets of electromagnetic energy

Question 3

Units of intensity are?

Answer 3

J/m2/s

Question 4

Electrons

Answer 4

Small negatively charged atomic particles

Question 5

Ions

Answer 5

Positively or negatively charged atoms

Question 6

Name the 3 types of ionising radiation

Answer 6

High energy ultraviolet, x-rays and gamma rays

Question 7

What type of radiation is present in the sun

Answer 7

Ultraviolet

Question 8

What are the problems of ultraviolet radiation

Answer 8

It can cause sunburn and skin cancer

Question 9

Property of gamma rays in relation to the body

Answer 9

They can pass through the human body easily

Question 10

Property of x-rays in relation to the body

Answer 10

They pass through muscle but are absorbed by bone

Question 11

How are radiographers protected from radiation

Answer 11

By lead and concrete screens

Question 12

You can increase the thermal energy transferred from radiation by…

Answer 12

Increasing it’s exposure time and intensity

Question 13

The green house effect

Answer 13

When the earth’s radiation is absorbed or reflected back and the earth gets warmer

Question 14

Principal frequency

Answer 14

The frequency with the greatest intensity

Question 15

Why has the level of Carbon dioxide steadily increased on the last 200 years?

Answer 15

The burning of fossil fuels as an energy source has increased the rate of release and deforestation to clear land has decreased the rate of absorption

Question 16

Global warming

Answer 16

The slow increase in the average temperature worldwide due to the greenhouse effect

Question 17

Because of what do computer models suggest that global warming will result in more extreme weather?

Answer 17

• Increased water vapour in the hotter atmosphere

- Increased convection wind speed

Question 18

Modulation

Answer 18

The process during which information is used to change the amplitude or frequency of the carrier wave

Question 19

Noise

Answer 19

Unwanted information which distorts the amplitude of the carrier continuously

Question 20

Bytes

Answer 20

The unit which digital information is stored as

Question 21

How many binary digits is a byte?

Answer 21

Eight

Question 22

Increasing the number of binary digits for a picture … The sharpness of the image

Answer 22

Increases

Question 23

Increasing the number of binary digits for a picture … Its quality

Answer 23

Increases

Question 24

Advantage of digital signals

Answer 24

They are easily stored in electronic memories so can be processed by computers

Question 25

What is the speed of light/ electromagnetic waves through a vacuum?

Answer 25

3 x 10^8 m/s

Question 26

Speed of light

Answer 26

3.0 x 10^5 km/s or 300,000 km/s