L02 Intro To Optics And Light

Question 1

Wave

Answer 1

A disturbance or oscillation that travels through space and matter, accompanied by a transfer of energy

Question 2

4 types of wave

Answer 2

Mechanical, electromagnetic, transverse and longitudinal

Question 3

Mechanical wave

Answer 3

Requires medium for propagation

Eg. water

Question 4

Electromagnetic wave

Answer 4

Able to propagate through vacuum

Eg. light

Question 5

Transverse wave

Answer 5

Components vibrate perpendicular to direction of propagation

Question 6

Longitudinal wave

Answer 6

Components vibrate parallel to direction of propagation

Question 7

Relationship btwn frequency and wavelength

Answer 7

↑ frequency : ↓ wavelength

↓ frequency : ↑ wavelength

Question 8

Formula for wavelength/frequency

Answer 8

Velocity = frequency x wavelength(m)

Question 9

Electromagnetic spectrum properties

Answer 9

• EM energy travels as transverse wave
• constant speed in vacuum at 3 x 10^8 m/s
• requires no medium to propagate

-Consists of varying electric and magnetic fields
•Vibrate perpendicular to each other and to direction of travel
•Vibrate at same frequency of the wave

• Unaffected by electric and magnetic fields
• Travel in straight line within limit set by diffraction
• Capable of being polarized
• Quantity of energy carried by the EM waves depends on magnitude of disturbance in the electric and magnetic fields
• Can be caused to produce interference effects

Question 10

List the waves on the electromagnetic spectrum from longest to shortest wavelength (lowest to highest frequency )

Answer 10

• Radiofrequency Wave
• Microwaves
• Infrared
• Visible Spectrum
• Ultraviolet (UV) Radiation
• X-rays
• Gamma Rays

Question 11

Terms describing light source

Answer 11

Source, point source, extended source, monochromatic source, polychromatic source

Question 12

Source

Answer 12

Any object that emits electromagnetic radiation

Question 13

Point source

Answer 13

A source either infinitely small or sufficiently far away

Question 14

Extended source

Answer 14

A source with measurable area

Question 15

Monochromatic source

Answer 15

A source that emits electromagnetic radiation of single wavelength or frequenc

Question 16

Polychromatic source

Answer 16

A source that emits radiation of several wavelengths or frequencies

Question 17

Wavefront

Answer 17

• Point source emit waves in all direction

* Arc / curve formed with centre at source by connecting same position e.g. trough / crest, on all waves

Question 18

Law of Malus

Answer 18

Rays are perpendicular to wavefronts

Question 19

Pencil rays

Answer 19

Group of rays emanating from a point source or single point on an extended source

Question 20

Types of pencil rays

Answer 20

• Divergent pencil
• Convergent pencil
• Parallel pencil

Question 21

Beam

Answer 21

Sum of all pencils emanating from a source or aimed towards an image

Question 22

Pencil vergence

Answer 22

• Divergent pencils = -ve vergence
• Convergent pencils = +ve vergence
• Parallel pencils = zero vergence

Question 23

Pinhole

Answer 23

One ray from object form one point on image

Question 24

Pinhole formula

Answer 24

h/h’=a/a’

Question 25

Depth of field

Answer 25

Distance object can move without affecting sharpness of image in specific fixed position

Question 26

Depth of focus

Answer 26

Distance image screen can move while maintaining sharp image for fixed object position