Photons & laser beams

Question 1

What is electromagnetic radiation emitted in?

Answer 1

Photons

Question 2

What are photons?

Answer 2

Packets of energy
(Electromagnetic waves)

Question 3

What is the wave equation?

Answer 3

E=(hc)/wavelength
Or
E=hf when f=c/wavelength

Question 4

What does h represent

Answer 4

Planck’s constant
6.63 * 10 ^-34

Question 5

Four properties of electromagnetic waves

Answer 5

1. Transverse waves
2. Propagation speed
3. No medium required for travel
4. Obey wave equation

Question 5

What does “transverse waves” mean?

Answer 5

Fields oscillate perpendicular to each other and to the direction of wave propagation.

Question 6

What is mean by “propagation speed”?

Answer 6

The speed the electromagnetic waves travel at

Question 7

What is the propagation speed of electromagnetic waves

Answer 7

3 * 10 ^8 ms^-1

Question 7

What are the properties of a light from a laser

Answer 7

Monochromatic (single frequency/wavelength) and instensity

Question 8

Photons in laser beams are…

Answer 8

Equal in frequency and energy

Question 8

Laser beam power equation

Answer 8

Power = (nhf) / wavelength

N = number of photons
H = planck’s constant
F = frequency

Question 9

What does n represent in reference to laser beams

Answer 9

Number of photons