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As a group What is electricity made of?

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Presentation on theme: "As a group What is electricity made of?"— Presentation transcript:

1 As a group What is electricity made of?
How can electricity have potential?

2 Electric Charges and Current

3 Electrical Potential Electricity has potential:
This energy comes from the charge particle has due to its position in an electric field. Because like charges repel, it takes energy to push a charged particle closer to another particle with a like charge. That energy is stored as the electric potential energy. These particles can move and want to/will when it is free to move.

4 Electric Current Electrical devices need a steady flow of electricity. The steady flow of charged particles is called electrical current. The flow continues until the energy source is used up, or disconnected. Electrical Current is measured in Amperes

5 Conductors Allow the easy flow of electricity, loosely bound electrons that are free to move from atom to atom metals like aluminum, gold, copper and silver are examples of good conductors.

6 Insulators Insulators – resists the flow of electrons making the object safe to handle plastic, rubber, glass Keep charges away from body

7 Resistors Resistors-allow electrons to flow but slow them down considerably. This allows the current to slow down.

8 electron movement in an insulator
electron movement in a conductor LG: to understand the basics of current electricity Current Electricity: the controlled flow of electrons through a conductor

9 Voltage Voltage – causes current to flow through an electrical circuit
Volt – unit of measure to measure this potential A Voltage Source (battery or generator) is required to maintain the electrical potential in a circuit.

10 Electrical Resistance
the opposition to the flow of electricity – measured in Ohms – symbol is the Greek letter Omega – Electricity will take the path of least resistance Ex: Lightning Rod The greater the resistance, the less current there is for a given voltage. a. Longer wires have greater resistance than short wires b. Thin wires have more resistance than thick wire c. High conductors have less resistance than insulators

11 Superconductors There are some materials that have practically no resistance at extremely low temperatures. These are called Superconductors. Superconductors have many uses including use in power lines to increase efficiency as well as in computers to improve speed.

12 Grounding As discussed charges/electricity likes to move through lines with lower resistance. Because of this we have developed a procedure known as grounding. Grounding means providing a harmless, low-resistance path-a ground- for electricity to flow. This is used to protect buildings from damage from lightning strikes. A “Lighting Rod” moves lighting strikes into the ground where the charge is absorbed.


14 What is ohms law? Ohm’s Law explains the relationship between voltage (V or E), current (I) and resistance (R) Used by electricians, automotive technicians, stereo installers

15 VOLTAGE (V) It is the push or pressure behind current flow through a circuit, and is measured in (V) volts. 

16 CURRENT Current refers to the quantity/volume of electrical flow. Measured in Amps (A)

17 RESISTANCE  Resistance to the flow of the current. Measured in Ohms

18 General Rule. 1. Assuming the resistance does not change:
As voltage increases, current increases. as voltage decreases, current decreases. 2.  Assuming the voltage does not change: As resistance increases, current decreases. As resistance decreases, current increases.

19 Chapter 5 Questions What is the difference between resistance and insulation? Describe some of the disadvantages of solar cells listed from your book. How can a lightning rod protect a building from fire? Describe why lightning strikes it rather than something else. How do rechargeable batteries work differently from nonrechargeable ones? Describe how we can increase or decrease electrical potential energy.

20 http://montage. baschools. org/SAFARI/montage/play. php

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