Chapte 11

Question 1

What are waves?

Answer 1

A physical phenomenon where it transfers energy through a medium without transferring matter

Question 2

What are the 2 types of waves?

Answer 2

Mechanical- particles of a medium oscillate

EM-electrostatic and magnetic fields in a medium vibrate

Question 3

What are the modes of vibration?

Answer 3

Transverse-direction of oscillation is perpendicular to direction of energy transfer
Longitudinal-direction of oscillation is parallel to direction of energy transfer

Question 4

What is displacement?

Answer 4

Distance and direction of a vibration particle from a equilibrium position

Question 5

What is the amplitude?

Answer 5

Maximum displacement of a vibration particle from the equilibrium position

Question 6

What is the wavelength?

Answer 6

Distance between 2 adjacent vibration particles with same velocity at same displacement

Question 7

What is the period?

Answer 7

Time taken for a particle to complete one oscillation

Question 8

What is the frequency?

Answer 8

Number of complete oscillations performed per second by a particle

Question 9

What is the wave equation?

Answer 9

Frequency*wave length=wave speed

Question 10

What is the phase?

Answer 10

Fraction of a complete cycle that a particle is at

Question 11

What is the phase difference?

Answer 11

The difference in phase between 2 points along the same wave or 2 waves at any given point

Question 12

What are wavefronts?

Answer 12

Lines of constant phase

Question 13

What is the law of reflection?

Answer 13

Angle of incidence=angle of reflection

Question 14

What is diffraction?

Answer 14

It’s the physical phenomenon of waves spreading out when passing through a gap

Question 15

What is the intensity equation?

Answer 15

I=P/A or I=P/4pi r^2

Question 16

Order of electromagnetic spectrum

Answer 16

Radio waves
Micro waves
Infrared waves
Visible light
Ultraviolet 
X rays
Gamma rays

Question 17

What are polarised filters?

Answer 17

Only allows EM waves which are polarised in the same plane to pass through

Question 18

What is refraction?

Answer 18

When a wave changes direction when crossing the boundary between 2 different media

Question 19

Refractive index

Answer 19

n=c/v

The greater the decrease in speed, the greater the refractive index of the medium and the more the light refracts

Question 20

Refractive index and angle of incidence and refraction

Answer 20

n1sin(01)=n2sin(02)
n1=refractive index of medium 1
n2=refractive index of medium 2
01=angle of incidence/refraction in medium 1
02=angle of incidence/refraction in medium 2

Question 21

What is critical angle?

Answer 21

Angle where if the angle of incidence exceeds it, the angle of refraction is 90°

Question 22

What must occur for total internal reflection to take place?

Answer 22

Critical angle must be exceeded

Refractive index of first medium must be higher than that of the second medium

Question 23

Equation for TIR

Answer 23

Sin0=n2/n1