Transcript electric light system

STUDENTS OF THE MADRAS SEVA SADAN HR.SEC.SCHOOL, CHETPUT, CHENNAI-31.
• Thomas
Alva
Edison invented the
electricity.
He
invented
electric
bulb, lamb,etc.
• The electric light
system was more
than
just
the
incandescent lamp,
or "light bulb."
Thomas Alva Edison was
born February 11, 1847 in
Milan, Ohio (pronounced MYlan). In 1854, when he was
seven, the family moved to
Michigan, where Edison spent
the rest of his childhood. At
the age of 12 he sold fruit,
snacks and newspapers on a
.
train as a "news butcher. He
even
printed
his
own
newspaper, the Grand Trunk
Herald, on a moving train
Electric current is the
continuous flow of electrons
through
a
conducting
material . Electrons are
invisible so to understand
the basics of how circuits
work, it helps to examine a
mechanical system that
behaves in many ways
similar to the electric circuit.
This mechanical system
consists of a pump pushing
water through a closed
pipe.
The phonograph was
the first machine that could
record the sound of
someone's voice and play
it back. In 1877, Edison
recorded the first words on
a piece of tin foil. He
recited the nursery rhyme
"Mary Had a Little Lamb,"
and
the
phonograph
played the words back to
him. This was invented by
a man whose hearing was
so poor that he thought of
himself as "deaf"!
“The amount of current flowing in a
circuit made up of pure resistances
is directly proportional to the
electromotive forces impressed on
the circuit and inversely
proportional to the total resistance
of the circuits
In simpler terms ohm’s Law:
A steady increase in voltage, in a
circuit with constant resistance,
produces a constant linear rise in
current.
Electric current is the rate of charge
flow past a given point in an electric
circuit, measured in coulombs/second
which is named amperes. In most DC
electric circuits, it can be assumed that
the
resistance to current flow is a
constant so that the current in the circuit is
related to voltage and resistance by ohm’s
law.
• The unit of electric charge is the coulomb.
Ordinary matter is made up of atoms which have
positively charged nuclei and negatively charged
electrons surrounding them. Charge is quantized
as a multiple of the electron or proton charge:
•
A bell that is made to sound by
closing a switch (bellpush), causing an
electric current to pass through an
electromagnet. This in turn causes a
hammer to strike the bell and in doing so
to break the circuit. The hammer then
springs back to a position that again
closes the circuit. The bell thus rings
continuously while the switch is closed.
• An electromagnet is a coil of wire, around an iron
core, that produces magnetism as long as an electric
current flows through the coil. An electromagnet's
can be turned on and off, making it useful in
operating electrical devices with movable magnetic
parts, such as generators, motors, clutches, and
other devices such as Metal detectors.
• The strength of the magnetic field depends on
several things,
1. The number of turns on the coil
2. The size of wire used to wind the coil
3. The Voltage source applied to the coil
• www.allenergy.com/electricity/el
ecnews.html
• www.heathkit.com/html/ee3100.html • www.physics.usyd.edu.au/teach
_res/mteach/mt83/w83.htm
• www.hydro.com.au/education/el
ectricity
• www.heathkit.com/html/ee3100.html - 26k