Uses and Dangers of Waves

Question 1

What do all waves of the electromagnetic spectrum have in common?

Answer 1

They all travel at the same speed through are a vacuum.

They are all transverse.

Question 2

What are the uses of radiowaves?

Answer 2

They have a very long wave length so they are used in:

• Broadcasting
• Communication

Question 3

Which end of the electromagnetic spectrum has the longest wave length?

Answer 3

• Radiowaves have the longest wavelength and it gets shorter from there.

Question 4

Which end of the electromagnetic spectrum has the lowest frequency?

Answer 4

• Radiowaves have the lowest frequency and it gets higher from there. (Gamma rays have the highest frequency)

Question 5

What are the uses of mircowaves?

Answer 5

• Satellite communication
• Cooking (the microwaves used in cooking are absorbed by the water molecules in food and transfer their energy to other parts of the food)

Question 6

What are the uses of infared?

Answer 6

Infared is also heat radiation so it can be used in:

• heaters
• night vision equipment

Question 7

What are the uses of visible light?

Answer 7

• optical fibres

- photography

Question 8

What are the uses of x-rays?

Answer 8

• Observing the internal structure of objects and materials

- This is used in medical applications (i.e. x-ray machines)

Question 9

What are the uses of gamma rays?

Answer 9

• sterilising food and medical equipment

Question 10

What is a useful anagram for remembering the order of the electromagnetic spectrum?

Answer 10

Raul’s Mother Is Visting Uncle Xavier’s Garden

Question 11

What are some of the dangers of microwaves?

Answer 11

• internal heating of body tissue

Question 12

What are the uses of ultaviolet light/

Answer 12

• fluorescent lamps

Question 13

What are some dangers of infrared?

Answer 13

• Skin burns

Question 14

What are some dangers of ultraviolet light?

Answer 14

• damage to surface cells and blindness

Question 15

What are some dangers of gamma rays?

Answer 15

• cancer/ cell mutation

Question 16

Describe a transverse wave.

Give some examples of transverse waves.

Answer 16

• In transverse waves the vibrations are at 90 degrees to the direction energy is transferred by the wave.
• Ripples on water; all waves on the electromagnetic spectrum.

Question 17

Describe a longitudinal wave.

Give some examples of longitundinal waves.

Answer 17

• In longitudinal waves the vibrations are along the same direction as the wave transfers energy. It has compressions and rarefactions.
• sound and ultra sound waves; shock waves.

Question 18

What is the amplitude of a wave?

Answer 18

The height of it from rest (the middle) to crest (the top of the peak).

Question 19

What is frequency?

What is it measured in?

Answer 19

How many complete waves there are passing a certain point per second.
Measured in hurtz (Hz)

Question 20

What is the time period?

What is it measured in?

Answer 20

The time is takes for one complete waves to pass a certain point.
Seconds.

Question 21

How do triangular prisms disperse white light?

Answer 21

Different wavelengths of light refract by different amounts.
A triangular prism does not have parallel boundaries (like a rectangular block does), so the different wave lengths in white light do not emerge parallel, because they have been refracted by different amounts.
This means white light has dispersed into the visible light spectrum and you get the rainbow effect.

Question 22

What is a way to remember the order of the visible light spectrum? (From the least refracted to the most refracted)

Answer 22

Richard Of York Gave Battle (In) Vain : Red Orange Yellow Green Blue (Infrared) Violet

Question 23

How does the refractive index of a media affect the speed of a wave that travels throught it?

Answer 23

The higher the refractive index, the slower the wave wil travel.

Question 24

What is the frequency range of human hearing?

Answer 24

20 - 20000 Hz