Waves

Question 1

What is frequency measured in?

Answer 1

Hertz (Hz)

Question 2

How are waves formed and what do they transport?

Answer 2

Waves are formed by vibrations and they transport Energy from one place to another

Question 3

Frequency is equal to

Answer 3

No. of Waves / Time

Question 4

Longitudinal Waves

Answer 4

Particles vibrate back and forth parallel to the direction in which the wave is travelling

Question 5

Examples of Longitudinal Waves

Answer 5

Sound + Ultrasound

Question 6

Transverse Waves

Answer 6

Particles vibrate up and down perpendicular to the direction in which the wave is travelling

Question 7

Examples of Transverse Waves

Answer 7

All Electromagnetic Waves, Water waves, S-Type Earthquakes

Question 8

(Wave Equation) Speed is equal to

Answer 8

Frequency x Wavelength (v = f x λ)

Question 9

What is Ultrasound

Answer 9

Frequencies that are higher than 20,000Hz

Question 10

What is the audible human hearing range?

Answer 10

20Hz - 20,000Hz

Question 11

What are some Ultrasound applications?

Answer 11

In Industry - Detecting Faults in Metals
In Medicine - Scanning soft tissues to diagnose cancers

Question 12

Sonar and radar both use

Answer 12

the principle of echo-location to detect objects

Question 13

Sonar is

Answer 13

Sound Navigation and Ranging (sound waves are used to locate objects under water)

Question 14

Radar is

Answer 14

Radio Detecting and Ranging - (EM waves are used to detect aircrafts and ships)

Question 15

Distance =

Answer 15

Speed x Time

Question 16

The Use of Gamma

Answer 16

Used to kill cancer cells and sterilize medical equipment

Question 17

The Use of X-Ray

Answer 17

To Diagnose Broken Bones

Question 18

The Use of UV (Ultraviolet)

Answer 18

Detect Forged Bank Notes

Question 19

The Use / Dangers of Visible

Answer 19

Used for Human Vision, Photography / Can cause Snow Blindness

Question 20

The Use / Dangers of Infrared

Answer 20

Toasters, Ovens, Tv remotes / Damages cells by Burning

Question 21

The Use / Dangers of Microwaves

Answer 21

Used in Mobile Phones + Satelites / Internal Heating of Body Tissues (cause eye Cataracts)

Question 22

The Use / Dangers of Radio

Answer 22

Tv and Radio Communications / No known Dangers

Question 23

The Dangers of Gamma, X-Ray and UV (Ultraviolet)

Answer 23

Can Disrupt DNA and cause Cancers

Question 24

Higher frequency waves cause ____ damage to cells?

Answer 24

More

Question 25

All Electromagnetic waves are

Answer 25

Transverse

Question 26

What speed do Electromagnetic waves travel at?

Answer 26

300 Million m/s in a Vacuum

Question 27

How do you measure angle of incidences and reflections?

Answer 27

From The Normal

Question 28

Angle of Incidence =

Answer 28

Angle of Reflection

Question 30

What is refraction?

Answer 30

The bending of light as it travels from one material to another

Question 31

Why does refraction happen?

Answer 31

Because light travels at different speeds in different materials. Air = 300 million m/s Water = 225 million m/s Glass = 200 million m/s

Question 32

What is Dispersion (of white light)?

Answer 32

The splitting of white light into the colours of the visible spectrum

Question 33

Why does dispersion happen?

Answer 33

Each colour travels the same speed in air but differently in glass

Question 34

Colour order of refractions

Answer 34

Red, Orange, Yellow, Green, Blue, Indigo, Violet

Question 35

What is Ohms Law?

Answer 35

The current through a wire is directly proportional, to the voltage across it, provided that the temp remains constant.

Question 36

Voltage =

Answer 36

Current x Resistance

Question 37

Why does resistance increase in a lamp over time?

Answer 37

Becomes the lamp becomes hotter