Waves-Progressive waves and refraction

Question 1

What is a progressive wave ?

Answer 1

Wave with a net transfer of energy and a constant amplitude.

Question 2

What is a stationary wave ?

Answer 2

Wave with no net transfer of energy and varying amplitude. ( made of 2 progressive waves with opposite propagation )

Question 3

What is a mechanical wave ?

Answer 3

Oscillations of particles.

Question 4

What is a electromagnetic wave ?

Answer 4

Oscillations of fields ( travel at c and are always transverse ).

Question 5

What is a longitudinal wave ?

Answer 5

Wave where oscillations are parralel to transfer of energy.

Question 6

What is a transverse wave ?

Answer 6

Oscillations are perpendicular to net transfer of energy( can be polarized ).

Question 7

What is c ?

Answer 7

Speed if light in a vacuum ( 3x10^8 )

Question 8

What is the amplitude of a wave ?

Answer 8

Its maximum displacement from the equilibrium position.

Question 9

What is the frequency of a wave ?

Answer 9

Number of cycles per second at a fixed position.

Question 10

What is the wavelength of a wave ?

Answer 10

Least distance between 2 particles that are in phase in a wave.

Question 11

What is phase difference ?

Answer 11

Fraction of a cycle difference between two oscillating particles or waves.

Question 12

What do displacement time graphs show ?

Answer 12

How one particle moves over time.

Question 13

What does a distance displacement graph show ?

Answer 13

Displacement of particles at one moment in time.

Question 14

What does 0 rad phase difference show ?

Answer 14

particles or waves being in phase.

Question 15

How mangy degrees is πrad ?

Answer 15

180°

Question 16

what is the formula for phase difference ?

Answer 16

Φ = Xx360/λ or Xx2π/λ

Question 17

what do you call particles which are at oppositesof their cycles ?

Answer 17

in antiphase.

Question 18

What is the EM spectrum ?

Answer 18

Radio waves
microwaves
infrared waves
visible light
ultraviolet
x-rays
gamma rays

Question 19

What is the formula for frequency ?

Answer 19

f = 1/t

Question 19

what is the formula for wave speed ?

Answer 19

C = Fλ

Question 19

How does polarization work ?

Answer 19

A transverse wave is passed through a polaroid which has small slits that only lets waves in one plane pass through only.

Question 20

What happens when a wave passes through 2 perpendicular polaroid’s ?

Answer 20

no transmission because at first no vertical plane is let through, secondly none of the horizontal plane can pass through therefore none of the wave can pass through.

Question 20

What is refractive index ?

Answer 20

Ration between speed of light in a vacuum and speed of light in a medium.

Question 20

Wat is the refractive index of a vacuum and air.

Answer 20

1

Question 21

what is the formula for refractive index ?

Answer 21

n = c/speed of light in medium

Question 22

What is snells law ?

Answer 22

n1sinθ = n2sinθ2

Question 23

What is dispersion ?

Answer 23

Where different wavelengths of light refract by a different amounts.

Question 24

What colors of light disperse the most and least ?

Answer 24

most - violet
least - red

Question 25

What is the critical angle ?

Answer 25

angle at which the angle of refraction is 90°

Question 26

what are the two conditions for total internal reflection ?

Answer 26

Ray travels from a high to low refractive index.
Angle of incidence is greater than the critical angle.

Question 27

What is attenuation ? How can it be fixed ?

Answer 27

Impure glass causes light to lose their intensity.

Having a high purity glass.

Question 28

What is modal dispersion ? How can it be fixed ?

Answer 28

Where the path is zigzag light and reflects a lot causes pulse broadening.

Making the fibre thinner.

Question 29

What is spectral dispersion ? How can it be fixed ?

Answer 29

Where the light has multiple frequencies which have different refractive indexes which causes the light pulses to be split up.

Using a wave with only one single wavelength.