Topic 1- Waves :)

Question 1

Describe a transverse wave and give 2 examples

Answer 1

A transverse wave vibrates perpendicular (at a right angle) to the direction of the energy)
Examples- light waves (all EM waves), water waves

Question 2

Describe a longitudinal wave ans give an example

Answer 2

A longitudinal wave vibrates parallel to the direction of energy. The only example of this is a sound wave

Question 3

Frequency

Answer 3

• Known as the number of waves to pass a point in one second
• Measured in Hz, symbol f
• Equations= f = N ÷ T
  = T = 1 ÷ f
  = V = f × wavelength

Question 4

Amplitude

Answer 4

• Known as the height of a wave from the centre to the peak or tje trough
• Measured in M, symbol of A

Question 5

Wavelength (lambda)

Answer 5

• Known as the distance between two similar points on a wave
• Measured in M, symbol of lambda (ƴ upside down)
• Equations= V = f × wavelength
  = Wavelength =D ÷ T

Question 6

Period, T

Answer 6

• Known as the time for ome wave to pass a point
• Measured in S, symbol of T
• Equations= T = 1 ÷ f

Question 7

Wavespeed

Answer 7

• Known as the distance travelled by one wave in a second
• Measured in ms‐¹, symbol V
• Equations= V = D÷ T
  V = f × wavelength

Question 8

Define a wave

Answer 8

A wave transfers energy by vibrations

Question 9

Define diffraction

Answer 9

Diffraction is the bending of a wave as it moves past/around an object

Question 10

Define Refraction

Answer 10

Refraction is the bending of light as it moves from one material to another due to a change in speed

Question 11

Define the relationship between diffraction and wavelengths

Answer 11

The longer the wavelength, the more diffraction
The shorter the wavelength, the less diffraction
Diffraction causes the shape of a wave to change, but the frequency and wavelength stay the same
High frequency, shorter wavelengths diffraction less
Lower frequency, longer wavelengths diffract more

Question 12

Name all of the waves included within the EM spectrum

Answer 12

Radio/TV waves -> Microwaves ->
Infrared waves -> Ultraviolet waves -> X-rays -> Gamma rays

Question 13

Define the relationship between frequency, wavelength and the EM spectrum

Answer 13

The higher the wavelength, the lower the frequency and energy.

Radio/ TV waves have the longest wavelength
Gamma rays have the largest frequency and energy rate

Question 14

State the speed in which all EM waves travel at

Answer 14

3×10‐⁸ ms-¹

Question 15

State the EM wave which has the highest frequency

Answer 15

Gamma rays

Question 16

State the EM wave which has the highest wavelength

Answer 16

Tv/radio waves

Question 17

State what happens to the frequency and energy as the wavelength increases

Answer 17

They decrease

Question 18

State what happens to the wavelength as the frequency and energy increase

Answer 18

It decreases

Question 19

Name a detector for each type or radiation-

Answer 19

Tv/radio- aerial
Microwaves- aerial
Infrared- photodiode
Visible light- photographic film
Ultraviolet- photographic film
X-rays- photographic film
Gamma rays- photographic film

Question 20

State a non- medical use for each of these EM waves-

Answer 20

Tv/radio- communication
Microwaves- cooking/ communication
Infrared- Night vision equipment
Visible light- light bulbs/ stars
Ultraviolet- scanning bank notes
X- rays- Airport security
Gamma rays- sterilisation of fruit and vegetables

Question 21

State the definition of refraction

Answer 21

“The change in direction of light as it moves from ome substance to another due to a change in speed”

Question 22

What is the incident ray?

Answer 22

The ray of light which enters a material

Question 23

What is the ange of light which enters a material called and whay is its symbol?

Answer 23

The incident angel, written as i

Question 24

What is the refracted ray?

Answer 24

The ray of light which is refracted as it leaves a material

Question 25

What is the angle of light which is refracted as it leaves a material and what is it's symbol?

Answer 25

The refracted angle, written as r

Question 26

Define "the normal"

Answer 26

The normal is a dashed line drawn at right angles to the material. It represents 0° It is where all angles are measured from using a protractor

Question 27

In what direction does the light go when there is an increase in speed?

Answer 27

Away from the normal

Question 28

In what direction does the light go when there is a decrease in speed?

Answer 28

Towards the normal

Question 29

Describe the relationship between frequency and refraction

Answer 29

The frequency always stays the same/ constant

Question 30

Describe what happens when light goes from a less dense medium to a more dense medium

Answer 30

Speed decreases, wavelength decreases and the angle of refraction is less than the angle of incidence

Question 31

Describe what happens when light goes from a more dense medium to a less dense medium

Answer 31

Speed increases, wavelength increases, and the angle of refraction is greater than the angle of incidence