Recap from last time

Who is this?

• Elon musk

• Giorgio Armani

• Kim Soo-Hyun

• Albert Einstein

What is LASER?

• Light Amplitude Super Emission of Radiation

• Light Applied by Spontaneous Emotion of Radiation

• Light Amplification by Spontaneous Emission of Radiation

• Light Amplification by Stimulated Emission of Radiation

The wavelength of visible light is ranged between...?

• 380 - 750 mm

• 380 - 750 nm

• 0 - 200 nm

• more than 10,600 nm

What is wavelength?

• The height of the wave from top to bottom

• The basic unit of the radiant energy

• The amount of intensity in the wave

• The horizontal distance between any two corresponding points on the wave

What is not the properties of LASER?

• Coherent

• Directional

• Loudness

• Monochromatic

Which of following is NOT correct?

• Photon is basic unit of this radiant energy

• The basic unit of energy is Hertz (Hz)

• Wavelength is inversely proportional to frequency

• Photons travel at a speed of light