Using light

Question 1

What is Morse code?

Answer 1

Digital code that uses long and short bursts of sound or light to represent letters of the alphabet

Question 2

What is a laser?

Answer 2

Source of high intensity light with a single frequency and direction

Question 3

Uses of lasers

Answer 3

surgery and dental treatments
guiding weapons
CD, DVD, and Blue-ray players
cutting materials such as steel plates

Question 4

Features of laser light

Answer 4

The waves emitted all have the same frequency and they are in sync with each-other.
All the crests and troughs line up.
In phase.

Question 5

What does ‘in phase’ mean?

Answer 5

Waves that are in step with each other. Their crests line up with other crests.

Question 6

What is monochromatic?

Answer 6

Describes a wave that has just one value for its wavelength. Monochromatic light waves contain only one colour

Question 7

How is laser light used in CDs?

Answer 7

There are billions of pits on the average CD. This digital information is read by the laser. As the disc spins, a laser reflects from its surface. When the light enters a pit there is no reflection, and so the detector reads a series of light pulses. The digital code is then converted into sounds or images by computer chips in the CD player.