Waves, superposition and refractive index

Question 1

What is a progressive wave

Answer 1

Wave carrying energy from one place to another - material is not transferred in the process

Question 2

Describe transverse waves

Answer 2

Displacement perpendicular to the direction of energy transfer

Question 3

Describe transverse waves

Answer 3

Displacement parallel to the direction of energy transfer

Question 4

Define amplitude

Answer 4

Maximum possible displacement of the wave

Question 5

Define wavelength

Answer 5

Distance between two repeating parts of a wave

Question 6

Define time period

Answer 6

Time between two repeating parts of a wave

Question 7

Define phase

Answer 7

Position of a certain point along a wave’s cycle

Question 8

What is phase difference

Answer 8

When different waves are in the same position in space but in different parts of their cycle

Question 9

How is a EM wave produced

Answer 9

Oscillation of perpendicular electric and magnetic fields

It stores energy within its field

Question 10

What is used by scientists to accelerate charged particles to produce intense EM waves

Answer 10

A synchotron

Question 11

What produces EM waves

Answer 11

Accelerating charged particles

Question 12

What waves can be polarised

Answer 12

Transverse waves as they oscillate in all directions

Question 13

When is a wave polarised

Answer 13

The wave is vibrating in only one direction

Question 14

Define intensity

Answer 14

Measure of power per unit area

P.S: Intensity is a measure of it’s amplitude squared - directly proportional to it

Question 15

Applications of polarisation

Answer 15

Sunglasses reduces glare with polarised light

Question 16

Malu’s Law

Answer 16

Intensity at detector = Intensity of wave x cos^2(theta)

theta = angle of polariser

Question 17

Stationary wave definition

Answer 17

When two progressive waves of the same frequency and amplitude but moving in opposite directions superpose

Question 18

What are nodes

Answer 18

Places where waves maximally destructively interfere

Question 19

What are antinodes

Answer 19

Places where waves maximally constructively interfere

Question 20

Factors effecting resonant frequency

Answer 20

Longer the string - the lower the resonant frequency
The heavier the string - the lower the resonant frequency
The lower the tension on the string - the lower the resonant frequency

Question 21

What is the resonant frequency

Answer 21

1st harmonic