SCIENCE 10
(2nd Quarter)
SCIENCE Wavelengths & Frequency are inversely
● Electromagnetic Waves & Application proportional.
● Radiation & radioactivity Frequency & Energy are directly
● Optics (Reflection & Refraction) proportional.
● Magnetism & Electricity
ELECTROMAGNETIC WAVES &
APPLICATION
Transverse Wave - particles vibrate
perpendicular to the direction of the wave’s
propagation.
Longitudinal Wave - particles vibrate Types of EM waves are defined by the
parallel to the direction the wave oscillates. energy photons carry.
James Clark Maxwell formulated the (PHOTONS - bundles of energy)
Electromagnetic theory which says that
an oscillating electric current is capable Energy of Photon
of radiating energy in the form of EM
waves. E = hf
Heinz Hertz discovered Hertzian waves
(radio waves). Hertz is the unit of h - Planck’s Constant (6.63 x 10^-34
measurement of frequency. joules second)
f - frequency
Electromagnetic Waves - the electric and
magnetic fields oscillate perpendicular to
each other and the direction of the
propagating waves.
PROPERTIES
1. All EM waves are Transverse.
2. Don’t require any medium to travel.
3. Travel at the speed of light (3 x 10^8
Electromagnetic Spectrum - a continuum ms) in a vacuum.
of EM waves arranged according to 4. They can be reflected/refracted.
frequency and wavelength. 5. They can be emitted or absorbed by
matter.
6. They all obey the wave equation.
7. Their frequencies don’t change as
they pass from one medium to another
but both wavelength and speed Microwaves - gives off EM waves that
change. bounces around an oven. The water
8. Carry energy from one place to molecules absorb the EM wave so food gets
another. hot.
9. They are all neutral charge. ● Radar communication
● Analysis of fine details
● Useful demonstration for macroscopic
scales
● Telephone communication.
RADAR (Radio Detection and Ranging)
TERRESTRIAL COMMUNICATION
CELLPHONE
Infrared Rays - heat is transferred.
● For navigation (through fog & haze)
● Medical Treatment
Visible Light - can be detected by the eye.
Seven colors of light. (Red, Orange, Yellow,
APPLICATION OF EM WAVES
Green, Blue, Indigo, Violet)
Radiowaves - longest wavelength, lowest
● Optical Fibers in Medicine &
frequency.
Telecommunications
● Radio and TV communication
● Radar and Satellite Communication
● Navigation, Ships, & Aircrafts
They are generated via transmitter and
detected via receiver. Antenna allows it to
send energy into space. Transmitters &
receivers operate over a limited range.
(increasing wavelength)
EM induction
Ultraviolet - main source is sunlight. It is
used to sterilize surgical instruments and Hans Christian Showed how
also kills bacteria and viruses. Oersted current wires
● Produces vitamin D behaves like a
● Gives tanning effect magnet
● Use for security Heinrich Heinz Showed
● Sterilize drinking fountains experimental
evidence of
X-rays - discovered by Wilhelm Conrad relations between
Roentgen (1895). Produce by rapid EM to light.
deceleration of fast-moving electrons.
● Diagnostic tool for dentistry and RADIATION & RADIOACTIVITY
medicine
● Use for security and inspection Radiation - the penetrating rays and
particles emitted by radioactive source.
Gamma rays - shortest wavelength, highest
frequency. Generated by changes in energy
Non-Ionizing Ionizing
levels in the nucleus.
● Useful for cancer treatment Radio waves Occurs in 2 forms
(rays and particles)
at the high energy
end of the EM
spectrum
Microwaves Carries sufficient
energy to knock
electrons off other
atoms which can
affect normal
biological
processes
Infrared Rays
Andrѐ Marie Demonstrated the Visible Light
Ampere magnetic effect
based on the Ultraviolet Rays
direction of current.
TYPES OF RADIATION
James Clark Contributed in
1. ALPHA PARTICLES - positively
Maxwell developing
equation to show charged identical to helium nucleus.
the relationship of (has 2 protons, 2 neutrons)
electricity and
magnetism
Michael Faraday Principle behind
Nuclear Fusion - combine nuclei to form a
heavier nucleus to release a large amount
of energy.
Nuclear Fission - nucleus splits into
2. BETA PARTICLES - electron from
smaller nuclei.
breaking a part of neutron in an atom.
REFER TO PERIODIC TABLE
SOURCES OF IONIZING RADIATION
Naturally - Occurring
1. Cosmic Radiation
2. Terrestrial Radiation
3. Radon
4. Internal Radiation
3. GAMMA RAYS - high energy photon Artificial Source
emitted by a radioisotope. 1. Medical Applications
2. Consumer Products
3. Fallout
4. Nuclear and Other Industries
HOW RADIATION INTERACTS WITH
MATTER?
● Ionization releases rays/particles
● Transfers energy to the electrons of the
Alpha Beta Gamma
material
Mass Heaviest Lighter No Mass
TWO FORMS OF TRANSFER
Speed Slowest Faster Speed of 1. IONIZATION - the energy transferred pulls
Light
electron from the atom.
Magnetic Deflected More Undeflect 2. EXCITATION - transfer is temporary.
Field Deflected ed (no Electron received enough energy to reach
charge) an excited state at a higher energy level.
Penetration Can’t Pass Pass
pass paper, paper and
paper Can’t aluminum,
(skin & pass Can’t pass
tissues) aluminum Lead
Ionization Most Can Lowest
Ionizing ionize Ionizing
Power
Half-Life - the amount of time it takes for Point of Incidence - point at which the
half of the unstable nuclei to decay. incident ray strikes the reflecting surface
Normal - line drawn perpendicular to the
mirror at the point of incidence
Reflected Ray - ray of light bouncing off.
PLAIN MIRROR
TYPES OF IMAGE FORMATION
● Virtual Images - can’t project on screen.
Always on the OPPOSITE side of the
OPTICS (LIGHT, REFLECTION & mirror.
REFRACTION)
Mirror - any smooth surface that reflects
light.
TYPES OF MIRROR
1. PLAIN MIRROR - mirror with Flat surface
and projects.
2. CURVED/SPHERICAL MIRROR
a. Concave/Converging
b. Convex/Diverging
TYPES OF REFLECTION
1. Regular - light rays are regularly reflected
in our eyes. ● Real Images - can project to screen.
2. Diffuse - light rays are reflected in different Projects on the same side.
direction.
SPHERICAL MIRROR
Convex Mirror (Diverging)
Incident Ray - ray of light falling on smooth
and highly polished surfaces like mirror
Concave Mirror (Converging)
RAY DIAGRAM - used to describe image
formed by spherical mirror.
MIRROR FORMULA
Lens
Refraction is the bending of light.
SPHERICAL LENS
Convex Lens (Converging) - outward
curved surface.
IMAGE FORMATION
Concave Lens (Diverging) - inward curved
surfaces.
IMAGE FORMATION
Magnetization - stroking ferromagnetic
materials in the same direction to make
magnets.
TYPES OF ARTIFICIAL MAGNETS
● Temporary - magnets that aren’t
always magnetic but can be turned
on at will.
● Permanent - magnets that
magnetics strength never fades.
LENS FORMULA
Iron, nickel, cobalt, aluminum, gadolinium,
and dyspronium are materials made into a
magnet but it needs an aloy to make the
magnetism last.
MAGNETISM & ELECTRICITY
USES OF MAGNETS
Magnetism - force exerted by a magnet ● Ships compass (navigation)
when it attracts/repel ● Electric motors
Magnet - substance that possesses ● Speakers
magnetic properties. It produces magnetic ● TV sets
field. Substances it attracts are called
Ferromagnetic. The closer magnets are the greater force
Magnetic Field - space around the magnet it releases. (vice versa)
where the force affects object.
Hans Christian Oersted (1819) -
Lodestone and Alnico are continuous flow of current generates a
PERMANENT/NATURAL magnets magnetic field. Oersted’s Law
Artificial Magnets - materials that are Electromagnet
made into magnets. Made by induced ● Can be switched on and off
magnetism. ● Solenoid with a core
● Can be made stronger by increasing
turns on the core
The direction of current changes in AC
generator.
Machael Faraday - moving wire in a
magnetic field could produce an electric
current. Electromagnetic Induction
Joseph Henry - current produced by
magnetic field is called induced current.
Electric Motor - a device that controls
electrical energy to mechanical energy.
Photoelectric Effect
A specific type of light allows electrons to
jump from one place to another. It knocks
electron off of an atom. Albert Einstein
formulate the hypothesis that light is made
Generator - device that transforms off both particles and wave called “wave
mechanical energy to electrical energy. packets”. This opened up the topic of
Operates base from electromagnetic quantum physics.
induction.
Ring is called Slip Ring Commutator if it
is AC generator.
