Waves and the Electromagnetic Spectrum

Question 1

What is the frequency of a wave?

Answer 1

The number of complete cycles of a wave passing a certain point.

Question 2

True of false? Transverse waves have sideways vibrations?

Answer 2

True

Question 3

Give 2 examples of longitudinal waves.

Answer 3

Sound waves and P-waves

Question 4

Calculate the frequency of a wave travelling at 2m/s with a wavelength of 3.5x10^-12

Answer 4

5.71428571x10^11

Question 5

Give 3 ways you can measure the speed of waves.

Answer 5

1) Using an oscilloscope
2) Water ripples and a strobe light.
3) Using a metal rod, hammer and a microphone connected to a computer

Question 6

Briefly describe refraction.

Answer 6

Waves Changing Direction at a Boundary

Question 7

Does the frequency of the wave change at all during refraction?

Answer 7

No.

Question 8

How do sound waves pass on energy?

Answer 8

Through rarefactions and compressions transferring energy through particles.

Question 9

What is the frequency of ultrasound?

Answer 9

Higher than 20,000Hz

Question 10

Give 2 uses of ultrasound.

Answer 10

Medical imaging and Industrial imaging.

Question 11

What is the frequency of infrasound?

Answer 11

Below 20Hz

Question 12

Give 2 animals that use infrasound for communication.

Answer 12

Elephants and whales

Question 13

Give 2 things that cause seismic waves.

Answer 13

Earthquakes and Explosions

Question 14

Can P-waves travel through the earth’s core?

Answer 14

Yes, S-waves can’t

Question 15

Describe P-waves

Answer 15

Longitudinal
They travel through solids and liquids
They travel faster than s-waves

Question 16

Describe S-waves

Answer 16

Transverse
Can only travel through solids
Slower the P-waves

Question 17

Complete:

Angle of incidence=?

Answer 17

Angle of reflection

Question 18

What does Total Internal reflection depend on?

Answer 18

The critical angle

Question 19

If the light ray enters a block at an angle larger than the critical angle, What happens?

Answer 19

No light comes out, it’s all internally reflected

Question 20

If light is reflected by something rough, does the surface look matted or shiny?

Answer 20

Matted

Question 21

Why do you need to do the refraction practical in a dim room.

Answer 21

So you can clearly see the ray

Question 22

Do different materials refract rays at different angles?

Answer 22

Yes, pure glass bends light more than plastic does.

Question 23

If white light travels through a green filter then a blue filter. What colour will the light be?

Answer 23

No light travels through.

Question 24

Why are objects different colours?

Answer 24

They reflect different wavelengths of light

Question 25

Which lens has a virtual Focus Point?

Answer 25

Concave Lens

Question 26

What does the power of a lens increase with?

Answer 26

The curvature

Question 27

Give the order of the Electromagnetic Spectrum from highest to lowest frequency.

Answer 27

Gamma, X-rays, UV, Visible, Infrared, Microwaves, Radiowaves

Question 28

What do all EM waves do?

Answer 28

Transfer energy to their surroundings.

Question 29

Which colour is the best emitter and absorb-er of EM waves?

Answer 29

Black

Question 30

Give 2 uses of Radio waves

Answer 30

Communication, broadcasting and used by satelites

Question 31

Give 2 uses of microwaves

Answer 31

Satellites, microwave ovens

Question 32

Give 2 uses of Infrared

Answer 32

Increase or monitor temperature, Thermal imaging, transferring information

Question 33

Give 2 uses of Visible Light

Answer 33

Photographs and illuminating things

Question 34

Give 2 uses of UV

Answer 34

UV lights, Security pens, Sterilising water.

Question 35

Give 2 uses of X-rays

Answer 35

Seeing inside things, airport security scanners

Question 36

Give 2 uses of Gamma rays

Answer 36

Sterilisation, tracers, cancer detection and treatment.