ET213 - Group 3: Electricity
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Transcript of ET213 - Group 3: Electricity
Electricity
The Power of Life
Outline of the Presenta6on
I. Charges II. Current III. Voltage
What are charges? An atom with one or more electrons missing becomes charged.
Two Types of Charges: Posi6ve Charge-‐ protons exceeds the number of electrons (+) Ex. Na+
Nega6vely Charge-‐electrons exceeds the number of electrons.(-‐) Cl-‐
Electrical Forces and Charges
The fundamental rule at the base of all electrical phenomena is that like charges repel and opposite charges a9ract.
How charges are transferred?
When electrons are transferred from the fur to the rod, the rod becomes nega6vely charged.
Charging by Induc6on
Principle of Conserva=on of Charge
Electrons are neither created nor destroyed but are simply transferred from one material to another.
What is a Current?
Current is the movement of charges in a circuit Electric current is measured in amperes, symbol A. An ampere is the flow of one coulomb of charge per second.
When the flow of charge past any cross sec6on is 1 coulomb (6.24 billion billion electrons) per second, the current is 1 ampere
What is Voltage
Voltage provides the energy to move the charges.(electrons) Important: charges cannot move in a circuit without poten6al difference across
Voltage Source
Power u6li6es use electric generators to provide the 120 volts delivered to home outlets This means that 120 joules of energy is supplied to each coulomb of charge that is made to flow in the circuit. A baVery is another source of voltage. It provide varying amounts depending on its nature and size.
References
www.hyperphysics.com