Electrical Safety,
Electrical Devices,
Electric Potential,
Capacitance,
Sources Of Energy And
Scientists
Tolentino, Danica Rose B.
Grade 12 – STEM C
General Physics II
Mrs. Eclavea
ELECTRICAL SAFETY
Electrical safety is a system of organizational measures and technical means to
prevent harmful and dangerous effects on workers from electric current, electric arc,
electromagnetic field and static electricity.
Electrical hazards can cause burns, shocks and electrocution (death).
Assume that all overhead wires are energized at lethal voltages. Never assume
that a wire is safe to touch even if it is down or appears to be insulated.
Never touch a fallen overhead power line. Call the electric utility company to
report fallen electrical lines.
Stay at least 10 feet (3 meters) away from overhead wires during cleanup and
other activities. If working at heights or handling long objects, survey the area
before starting work for the presence of overhead wires.
If an overhead wire falls across your vehicle while you are driving, stay inside
the vehicle and continue to drive away from the line. If the engine stalls, do
not leave your vehicle. Warn people not to touch the vehicle or the wire. Call
or ask someone to call the local electric utility company and emergency
services.
Never operate electrical equipment while you are standing in water.
Never repair electrical cords or equipment unless qualified and authorized.
Have a qualified electrician inspect electrical equipment that has gotten wet
before energizing it.
If working in damp locations, inspect electric cords and equipment to ensure
that they are in good condition and free of defects, and use a ground-fault
circuit interrupter (GFCI).
Always use caution when working near electricity.
Electrical Safety-Related Work Practices
Only qualified workers who have been trained in the avoidance of electrical hazards
are permitted to work on or near exposed energized parts. Safety related work
practices are employed to prevent electric shock or other injuries resulting from
either direct or indirect electrical contact when work is performed near or on
equipment or circuits which are or may be energized. The specific safety-related
work practices must be consistent with the nature and extent of the associated
electrical hazards.
ELECTRIC DEVICES
Electric Devices is a device that trips like a switch and opens the circuit when overloaded.
closed circuit, loop. a complete electrical circuit around which current flows or a signal circulates.
Coil. reactor consisting of a spiral of insulated wire that introduces inductance into a circuit.
Electrical devices take the energy of electric current and transform it in simple ways into some
other form of energy
What are some examples of electrical devices and their uses?
Transformer- Steps up or steps down the voltage at transmission and distribution level both.
But the power transfer remains the same :) great machine
Motor- Uses electrical energy for a mechanical operation. Used in escalators,elevators, etc.
Works on the principal of Electrodynamic induction.
Generator- Vice versa of Motor and same principal of operation
Resistor- A device that opposes the flow of current . Can be used where current parameters
are to be changed
Capacitor - Stores and releases energy in the form of electrostatic field. It cannot allow sudden
change of voltage.
Inductor- Stores energy in the form of electromagnetic waves. It cannot allow sudden change
of current due to practical reasons which you have to understand yourself
What is the difference between electronic and electrical devices?
When the field of electronics was invented in 1883, electrical devices had already been around for
at least 100 years.
The first electric batteries were invented by a fellow named Alessandro Volta in 1800. Volta’s
contribution is so important that the common volt is named for him. (There is some
archeological evidence that the ancient Parthian Empire may have invented the electric battery
in the second century BC, but if so we don’t know what they used their batteries for, and their
invention was forgotten for 2,000 years.)
The electric telegraph was invented in the 1830s and popularized in America by Samuel
Morse, who invented the famous Morse code used to encode the alphabet and numerals into
a series of short and long clicks that could be transmitted via telegraph. In 1866, a telegraph
cable was laid across the Atlantic Ocean allowing instantaneous communication between the
United States and Europe.
All of these devices, and many other common devices still in use today, such as light bulbs,
vacuum cleaners, and toasters, are known as electrical devices. So what exactly is the
difference between electrical devices and electronic devices?
The answer lies in how devices manipulate electricity to do their work. Electrical devices
take the energy of electric current and transform it in simple ways into some other form of
energy — most likely light, heat, or motion. The heating elements in a toaster turn electrical
energy into heat so you can burn your toast. And the motor in your vacuum cleaner turns
electrical energy into motion that drives a pump that sucks the burnt toast crumbs out of your
carpet.
In contrast, electronic devices do much more. Instead of just converting electrical energy
into heat, light, or motion, electronic devices are designed to manipulate the electrical current
itself to coax it into doing interesting and useful things.
That very first electronic device invented in 1883 by Thomas Edison manipulated the
electric current passing through a light bulb in a way that let Edison create a device that could
monitor the voltage being provided to an electrical circuit and automatically increase or
decrease the voltage if it became too low or too high.
One of the most common things that electronic devices do is manipulate electric current in
a way that adds meaningful information to the current. For example, audio electronic devices
add sound information to an electric current so that you can listen to music or talk on a
cellphone. And video devices add images to an electric current so you can watch great movies
until you know every line by heart.
Keep in mind that the distinction between electric and electronic devices is a bit blurry.
What used to be simple electrical devices now often include some electronic components in
them. For example, your toaster may contain an electronic thermostat that attempts to keep
the heat at just the right temperature to make perfect toast.
And even the most complicated electronic devices have simple electrical components in
them. For example, although your TV set’s remote control is a pretty complicated little
electronic device, it contains batteries, which are simple electrical devices.
ELECTRIC POTENTIAL AND CAPACITANCE
ELECTRIC POTENTIAL
Electric potential energy is the energy a charge has due to its position relative to
other charges. If you take a ball with mass m and raise it to any height, you are giving
it gravitational potential energy. We know this for two reasons: one, you have to use
energy in your muscles to do it, and two, when you let go of the ball, it falls to the
ground and that energy is released again.
Electric potential energy is similar but with charges instead of masses. Instead of
raising a ball in the gravitational field of the Earth, you move a charge that's in the
electric field of another charge. By separating two charges to a radius r, you are
giving the charges electric potential energy relative to each other. When you release
those charges, they will attract or repel, releasing that energy. Opposite charges will
attract, just like the Earth and the ball. Like charges will repel.
CAPACITANCE
Capacitance is the ability of the capacitor to store energy.
Capacitors are an electric device relatively few people know about. But that might be
considered surprising, particularly when you realize that practically every electronic
device will contain capacitors of some kind. A capacitor is a component that stores
charge (stores electrical energy) until it gets full and then releases it in a burst.
There are many reasons why you might want to do that. You might store charge in a
capacitor in case you lose external power, so that the device doesn't die instantly,
allowing recovery processes to complete. You might want a circuit to get a regular
'pulse' of energy every x amount of time. But, whatever the reason, capacitors come
in all kinds of sizes, holding anything from tiny amounts of energy to huge amounts.
Capacitors really are used everywhere: from computers to televisions to high-band
pass filters to car starters. Almost every electronic device you use contains capacitors.
And the title of this lesson: capacitance is a measure of a capacitor's ability to store
charge, measured in farads; a capacitor with a larger capacitance will store more
charge.
ENERGY SOURCE
- A source from which useful energy can be extracted or recovered either directly or by means of a
conversion or transformation process.
- Renewable (sun, sea, wind) or non-renewable (coal mine, gas well, oil well) resources used for
obtaining an energy source.
Renewable energy
is energy that is collected from renewable resources, which are naturally replenished on
a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable
energy often provides energy in four important areas: electricity generation, air and water
heating/cooling, transportation, and rural (off-grid) energy services.
Non-renewable resource
(also called a finite resource) is a resource that does not renew itself at a sufficient rate for
sustainable economic extraction in meaningful human time-frames. An example is carbon-based,
organically-derived fuel. The original organic material, with the aid of heat and pressure, becomes
a fuel such as oil or gas. Earth minerals and metalores, fossil fuels (coal, petroleum, natural gas)
and groundwater in certain aquifers are all considered non-renewable resources, though
individual elements are almost always conserved
10 Different Energy Sources
1. Solar Energy
Solar power harvests the energy of the sun through using collector panels to create
conditions that can then be turned into a kind of power. Large solar panel fields are often used in
desert to gather enough power to charge small substations, and many homes use solar systems to
provide for hot water, cooling and supplement their electricity. The issue with solar is that while
there is plentiful amounts of sun available, only certain geographical ranges of the world get enough
of the direct power of the sun for long enough to generate usable power from this source.
2. Wind Energy
Wind power is becoming more and more common. The new innovations that are allowing
wind farms to appear are making them a more common sight. By using large turbines to take
available wind as the power to turn, the turbine can then turn a generator to produce electricity.
While this seemed like an ideal solution to many, the reality of the wind farms is starting to reveal
an unforeseen ecological impact that may not make it an ideal choice.
3. Geothermal Energy
Geothermal energy is the energy that is produced from beneath the earth. It is clean,
sustainable and environment friendly. High temperatures are produced continuously inside the
earth’s crust by the slow delay of radioactive particles. Hot rocks present below the earth heats up
the water that produces steam. The steam is then captured that helps to move turbines. The
rotating turbines then power the generators.
4. Hydrogen Energy
Hydrogen is available with water(H2O) and is most common element available on earth.
Water contains two-thirds of hydrogen and can be found in combination with other elements.
Once it is separated, it can be used as a fuel for generating electricity. Hydrogen is a tremendous
source of energy and can be used as a source of fuel to power ships, vehicles, homes, industries
and rockets. It is completely renewable, can be produced on demand and does not leave any toxic
emissions in the atmosphere.
5. Tidal Energy
Tidal energy uses rise and fall of tides to convert kinetic energy of incoming and outgoing
tides into electrical energy. The generation of energy through tidal power is mostly prevalent in
coastal areas. Huge investment and limited availability of sites are few of the drawbacks of tidal
energy. When there is increased height of water levels in the ocean, tides are produced which rush
back and forth in the ocean. Tidal energy is one of the renewable source of energy and produce
large energy even when the tides are at low speed.
6. Wave Energy
Wave energy is produced from the waves that are produced in the oceans. Wave energy is
renewable, environment friendly and causes no harm to atmosphere. It can be harnessed along
coastal regions of many countries and can help a country to reduce its dependance on foreign
countries for fuel. Producing wave energy can damage marine ecosystem and can also be a source
of disturbance to private and commercial vessels. It is highly dependent on wavelength and can
also be a source of visual and noise pollution.
7. Hydroelectric Energy
What many people are not aware of is that most of the cities and towns in the world rely on
hydropower, and have for the past century. Every time you see a major dam, it is providing
hydropower to an electrical station somewhere. The power of the water is used to turn generators
to produce the electricity that is then used. The problems faced with hydropower right now have to
do with the aging of the dams. Many of them need major restoration work to remain functional
and safe, and that costs enormous sums of money. The drain on the world’s drinkable water
supply is also causing issues as townships may wind up needing to consume the water that provides
them power too.
8. Biomass Energy
Biomass energy is produced from organic material and is commonly used throughout the
world. Chlorophyll present in plants captures the sun’s energy by converting carbon dioxide from
the air and water from the ground into carbohydrates through the process of photosynthesis.
When the plants are burned, the water and carbon dioxide is again released back into the
atmosphere. Biomass generally include crops, plants, trees, yard clippings, wood chips and animal
wastes. Biomass energy is used for heating and cooking in homes and as a fuel in industrial
production. This type of energy produces large amount of carbon dioxide into the atmosphere.
9. Nuclear Power
While nuclear power remains a great subject of debate as to how safe it is to use, and
whether or not it is really energy efficient when you take into account the waste it produces – the
fact is it remains one of the major renewable sources of energy available to the world. The energy
is created through a specific nuclear reaction, which is then collected and used to power
generators. While almost every country has nuclear generators, there are moratoriums on their use
or construction as scientists try to resolve safety and disposal issues for waste.
10. Fossil Fuels (Coal, Oil and Natural Gas)
When most people talk about the different sources of energy they list natural gas, coal and
oil as the options – these are all considered to be just one source of energy from fossil fuels. Fossil
fuels provide the power for most of the world, primarily using coal and oil. Oil is converted into
many products, the most used of which is gasoline. Natural gas is starting to become more
common, but is used mostly for heating applications although there are more and more natural gas
powered vehicles appearing on the streets. The issue with fossil fuels is twofold. To get to the fossil
fuel and convert it to use there has to be a heavy destruction and pollution of the environment.
The fossil fuel reserves are also limited, expecting to last only another 100 years given are basic
rate of consumption.
SCIENTISTS
Michael Faraday FRS (/ˈfæ.rəˌdeɪ/; 22 September 1791 – 25
August 1867) was an English scientist who contributed to the
study of electromagnetism and
electrochemistry. His main discoveries include the principles
underlying
electromagnetic induction,
diamagnetism and electrolysis.
Although Faraday received little formal education, he was one of
the most influential scientists in history. It was by his research on
the magnetic field around a conductor carrying a direct
current that Faraday established the basis for the concept of
the electromagnetic field in physics. Faraday also established
that magnetism could affect rays of light and that there was an
underlying relationship between the two phenomena. He similarly discovered the principles of
electromagnetic induction and diamagnetism, and the laws of electrolysis.
His inventions of electromagnetic rotary devices formed the foundation of electric motor
technology, and it was largely due to his efforts that electricity became practical for use in
technology.
As a chemist, Faraday discovered benzene, investigated the clathrate hydrate of chlorine,
invented an early form of the Bunsen burner and the system of oxidation numbers, and
popularised terminology such as "anode", "cathode", "electrode" and "ion". Faraday ultimately
became the first and foremost Fullerian Professor of Chemistry at the Royal Institution, a
lifetime position.
Faraday was an excellent experimentalist who conveyed his ideas in clear and simple language;
his mathematical abilities, however, did not extend as far as trigonometry and were limited to the
simplest algebra. James Clerk Maxwell took the work of Faraday and others and summarized it
in a set.
Benjamin Franklin
Benjamin Franklin FRS FRSE (January 17, 1706
[O.S. January 6, 1705]– April 17, 1790) was an
American polymath and one of the Founding Fathers of the
United States. Franklin was a leading author, printer, political
theorist, politician, freemason, postmaster, scientist, inventor,
humorist, civic activist, statesman, and diplomat. As a
scientist, he was a major figure in the American
Enlightenment and the history of physics for his discoveries
and theories regarding electricity. As an inventor, he is known
for the lightning rod, bifocals, and the Franklin stove, among
other inventions.He founded many civic organizations,
including Philadelphia's fire department and the University of
Pennsylvania.
Franklin earned the title of "The First American" for his early and indefatigable campaigning
for colonial unity, initially as an author and spokesman in London for several colonies. As the
first United States Ambassador to France, he exemplified the emerging American nation.
Franklin was foundational in defining the American ethos as a marriage of the practical values of
thrift, hard work, education, community spirit, self-governing institutions, and opposition to
authoritarianism both political and religious, with the scientific and tolerant values of
the Enlightenment. In the words of historian Henry Steele Commager, "In a Franklin could be
merged the virtues of Puritanism without its defects, the illumination of the Enlightenment
without its heat." To Walter Isaacson, this makes Franklin "the most accomplished American of
his age and the most influential in inventing the type of society America would become."
Charles-Augustin de Coulomb
Charles-Augustin de Coulomb
(/ˈkuːlɒm, -loʊm, kuːˈlɒm, -ˈloʊm/;French: [kulɔ]̃ ; 14
June 1736 – 23 August 1806) was a French military
engineer and physicist. He is best known for developing
what is now known as Coulomb's law, the description
of the electrostatic force of attraction and repulsion, but
also did important work on friction.
The SI unit of electric charge, the coulomb, was named
in his honour in 1908.
Charles-Augustin de Coulomb was born in Angoulême, Angoumois county, France, to Henry
Coulomb, an inspector of the royal demesne originally from Montpellier, and Catherine Bajet.
He was baptised at the parish church of St. André. The family moved to Paris early in his
childhood, and he studied at Collège Mazarin. His studies included philosophy, language and
literature. He also received a good education in mathematics, astronomy, chemistry and botany.
When his father suffered a financial setback, he was forced to leave Paris, and went to
Montpellier. Coulomb submitted his first publication to the Society of Sciences in Montpellier
during this time. He went back to Paris and passed the exams for the École royale du génie de
Mézières in 1760.
He graduated in 1761 and joined the French army as an engineer in the rank of lieutenant. Over
the next twenty years, he was posted to a variety of locations where he was involved in
engineering: structural, fortifications, soil mechanics, as well as other fields of engineering. His
first posting was to Brest but in February 1764 he was sent to Martinique, in the West Indies,
where he was put in charge of building the new Fort Bourbon and this task occupied him until
June 1772. His health suffered setbacks during the three years he spent in Martinique that would
affect him for the rest of his life.
On his return to France, Coulomb was sent to Bouchain. However, he now began to write
important works on applied mechanics and he presented his first work to the Académie des
Sciences in Paris in 1773. In 1779 Coulomb was sent to Rochefort to collaborate with the
Marquis de Montalembert in constructing a fort made entirely from wood near Île-d'Aix. During
his period at Rochefort, Coulomb carried on his research into mechanics, in particular using the
shipyards in Rochefort as laboratories for his experiments.
Upon his return to France, with the rank of Captain, he was employed at La Rochelle, the Isle of
Aix and Cherbourg. He discovered first an inverse relationship of the force between electric
charges and the square of its distance and then the same relationship between magnetic poles.
Later these relationships were named after him as Coulomb's law.
James Clerk Maxwell
James Clerk Maxwell, (born June 13, 1831, Edinburgh, Scotland—
died November 5, 1879, Cambridge, Cambridgeshire, England),
Scottish physicist best known for his formulation of electromagnetic
theory. He is regarded by most modern physicists as the scientist of
the 19th century who had the greatest influence on 20th-
century physics, and he is ranked with Sir Isaac Newton and Albert
Einstein for the fundamental nature of his contributions. In 1931, on
the 100th anniversary of Maxwell’s birth, Einstein described the
change in the conception of reality in physics that resulted from Maxwell’s work as “the most
profound and the most fruitful that physics has experienced since the time of Newton.”
The concept of electromagnetic radiation originated with Maxwell, and his field equations, based
on Michael Faraday’s observations of the electric and magnetic lines of force, paved the way for
Einstein’s special theory of relativity, which established the equivalence of mass and energy.
Maxwell’s ideas also ushered in the other major innovation of 20th-century physics,
the quantum theory. His description of electromagnetic radiation led to the development (according
to classical theory) of the ultimately unsatisfactory law of heat radiation, which prompted Max
Planck’s formulation of the quantum hypothesis—i.e., the theory that radiant-heat energy is emitted
only in finite amounts, or quanta. The interaction between electromagnetic radiation and
matter, integral to Planck’s hypothesis, in turn has played a central role in the development of the
theory of the structure of atoms and molecules.
André-Marie Ampère
André-Marie Ampère, (born Jan. 22, 1775, Lyon, France—died
June 10, 1836, Marseille), French physicist who founded and
named the science of electrodynamics, now known
as electromagnetism. His name endures in everyday life in
the ampere, the unit for measuring electric current.
Ampère, who was born into a prosperous bourgeois family during
the height of the French Enlightenment, personified the
scientific culture of his day. His father, Jean-Jacques Ampère, was
a successful merchant, and also an admirer of the philosophy of Jean-Jacques Rousseau, whose
theories of education, as outlined in his treatise Émile, were the basis of Ampère’s education.
Rousseau argued that young boys should avoid formal schooling and pursue instead an “education
direct from nature.” Ampère’s father actualized this ideal by allowing his son to educate himself
within the walls of his well-stocked library.
Had Ampère died before 1820, his name and work would likely have been forgotten. In that
year, however, Ampère’s friend and eventual eulogist François Arago demonstrated before the
members of the French Academy of Sciences the surprising discovery of Danish physicist Hans
Christiaan Ørsted that a magnetic needle is deflected by an adjacent electric current. Ampère was
well prepared to throw himself fully into this new line of research.
Ampère immediately set to work developing a mathematical and physical theory to understand
the relationship between electricity and magnetism. Extending Ørsted’s experimental work,
Ampère showed that two parallel wires carrying electric currents repel or attract each other,
depending on whether the currents flow in the same or opposite directions, respectively. He also
applied mathematics in generalizing physical laws from these experimental results. Most
important was the principle that came to be called Ampère’s law, which states that the mutual
action of two lengths of current-carrying wire is proportional to their lengths and to the
intensities of their currents. Ampère also applied this same principle to magnetism, showing the
harmony between his law and French physicist Charles Augustin de Coulomb’s law of magnetic
action. Ampère’s devotion to, and skill with, experimental techniques anchored his science
within the emerging fields of experimental physics
