POINTS TO REMEMBER IN UNIT II:
Module 1: Electromagnetism
A. Home recording Studio Start Up Equipment
Headphone
-. It is use for “referencing” or for checking what the mix would sound like on the equipment.
Studio monitor
- It is commonly known as speakers but these give a sound close enough to the real sound input.
Audio Interface
- A start-up equipment in which microphones and musical instruments are plugged into this, which in turn is
connected to the computer.
Digital Audio Software
- It is used for playing some digital instruments, recording, adding effects, and mixing different sources of sound
signals.
Condenser or dynamic microphone
-It refers to a recording studio equipment that converts sound into electrical signals
B. Magnetism
Pole / Polarity
-
refers to the North and South of a magnet.
Part where the force of attraction of a magnet is strongest
Magnetism - force of attraction created by a magnet.
Metallic materials – can be attracted by a magnet like iron.
Note : Like poles of a magnet ATTRACT and unlike poles REPEL. Similarly, if two unlike poles placed near
each other, the lines of force will connect the poles.
Magnetic field
-refers to a region around a magnet in which a magnetic force act
Note: When a bar magnet is broken into half, each half will automatically have its north and south pole.
Temporary Magnet
– happens when a nail can pick up a paper clip after it touches a magnet.
Note:
*When a bar magnet is often dropped, it loses its magnetism.
*Attraction between permanent magnet and induced magnet happen after magnetic induction
C. Electromagnetism
- Electricity and magnetism
 If a bar magnet is moved in and out of a coil of copper wire, electric current will flow through the wire
MODULE 2: The Electromagnetic Spectrum
Notes:
 In the electromagnetic wave, the direction of the propagation of the wave is perpendicular to the electric and
magnetic field directions.
 All electromagnetic spectrum have the same speed through a vacuum.
 electromagnetic waves in the order from the longest to the shortest wavelength:
RADIOWAVES
MICROWAVES
INFRARED RAY
VISIBLE LIGHT
ULTRA VIOLET (UV) RAY
X--RAY
GAMMA RAY






The speed of the electromagnetic wave in a vacuum is similar t the speed of light which is 3 x 10 8
X-rays and Gamma rays –lies at the ends of EM Spectrum
Visible Light – the only EM wave that can be seen by the human eye.
Radio waves- have the widest frequency range and are used for radar signals and communication.
4 x 10 14 - 7.5 x 1014 Hz is the range of frequencies are our eyes sensitive to.
3 x 10 8 m/s is the value of speed of light or EM waves.
MODULE 3: Mirrors and Lenses
A. The Human Eye:
Cornea - . It allows the passage of light into the eye and it also focuses the light.
Retina - It refers to the parts of the human eye that converts light waves to electrical signals
Sclera - A tough white skin made of tissue that covers all of the eyeball.
B.
Mirror
Convex mirror- A kind of mirror is used in automobiles and trucks to give the driver a wider area and smaller image of traffic
behind; also used in department stores.
Concave mirror- A type of mirror do dentists usually use to see clearly the images of our teeth