Chapter 12 - Using Waves Flashcards Preview

Edexcel GCSE Physics > Chapter 12 - Using Waves > Flashcards

Flashcards in Chapter 12 - Using Waves Deck (30):
1

How do waves at one end of the EM spectrum differ from waves at the other end? (2 marks)

- One end is high frequency, short wavelength - Other end is low frequency, long wavelength

2

What 4 properties do all waves have? (4 marks)

- All transfer energy - All transverse waves - Travel at the speed of light in a vacuum - All can be reflected, refracted and diffracted

3

Radio waves have the ....... wavelength in the EM spectrum (1 mark)

Longest, meaning low frequency

4

How are radio waves used in TV and FM radio (3 marks)

- Given out by a transmitter - As they cross an aerial, they are detected and info they carry can be received - TV and FM radio use radio waves with short wavelengths to carry their signals

5

What are the sources and detectors for radio waves (2 marks)

Sources - Radio and TV transmitters Detectors - Radio and TV aerials

6

Microwaves have a .... wavelength and a ... frequency (2 marks)

- Long - Low

7

How do microwaves heat food (5 marks)

- Special electrical circuits produce microwaves - Metal guides direct microwaves towards a rotating reflector - This reflector sends microwaves in all directions - Microwaves are reflected from metal casing - Food absorbs microwaves and becomes hot

8

Two uses of microwaves (4 marks)

- Cooking : microwaves are used as food absorbs microwaves and becomes hot - Phones : messages sent to and from mobile phones are also carried by microwaves

9

What are the sources and detectors for microwaves (2 marks)

Sources - microwave transmitters and ovens Detectors - microwave receivers

10

Describe two differences between X-rays and visible light (2 marks)

- X-rays have shorter wavelength - X-rays have higher frequency

11

State the name of the type of wave that includes X-rays and visible light

electromagnetic

12

Which of the following is NOT a medical use of X-rays? A - Pre-natal scanning B - CT scans C - Killing Cancer Cells

A - Pre-natal scanning

13

True or false? X-rays can be used to diagnose dental problems.

True

14

Are X-rays absorbed or transmitted by metal?

absorbed

15

True or false? X-rays can be used to break up kidney stones.

False

16

EM SPECTRUM ACRONYM

Raging

Martians

Invaded

Venus

Using

X-ray

Guns

17

A microwave cooker is often said to 'cook the food from the inside'

Explain whether this statement is true by describing how energy is transferred to heat up all of the potato [3 marks]

- Microwaves are electromagnetic waves

 - They cause water molecules to vibrate more / heat water

- Conduction through the rest of the potato

18

Q image thumb

- Electromagnetic induction

- Coil creates magnetic field around it

 - Which cuts through the metal pan

- Inducing a voltage in the pan;

- Causing a current in the pan

- Current makes the pan get hot

- Which heats the water by conduction

- Water convects energy to potato;

19

Suggest a property of radio waves that makes them suitable for use in communication [1 mark]

Can travel long distances

20

Describe a possible harmful effect on people of microwaves [1 marks]

heating

21

Describe a use of ultraviolet rays [1 marks]

kill bacteria

22

Possible harmful effect on people of ultraviolet rays [1 marks]

skin cancer

23

Explain what is meant by a digital signal [2 marks]

- Signal has two values

24

Suggest two ways that this signal could be made to carry more information [2 marks]

- Increased frequency of wave

- using increased bandwidth;

25

Q image thumb

C

26

Q image thumb

A

27

Q image thumb

C

28

Gamma radiation is used in hospitals even though it can be dangerous. Describe one use of gamma radiation in hospitals. 
(2)

- sterilising medical equipment; gamma kills bacteria; 
 - treating cancer/mutates cancer cells; radiotherapy/focused gamma rays; 
 - detecting cancer; PET scanner/(radioactive) tracers/gamma camera; 

29

Explain the risks to patients and doctors of using gamma radiation. (2)

- increased risk of cancer/mutation of cells damage to neighbouring/good/healthy cells 
 - radiation is ionising gamma has high/highest energy  
 - patient is only exposed for a short period of time doctor has continual (low level) exposure 

30

 State one way of reducing the risks to a doctor who uses gamma radiation. (1)

- (use for a) limited time

- idea of working at a distance/in another room