Current, Volts and Resistance (Ohm’s Law)

Slides:



Advertisements
Similar presentations
Current Electricity & Ohm's Law.
Advertisements

Cells have positive and negative electrodes.
What is Electricity? Electricity is the flow of moving electrons. When the electrons flow it is called an electrical current.
Electric Current: Basics. Current Electricity Current electricity is like current in a river. A high or fast river current means the water is rushing.
Use Ohm’s Law to solve the following equations.
Concept Summary Batesville High School Physics. Potential Difference  Charges can “lose” potential energy by moving from a location at high potential.
Resistance and Ohm’s Law. Current Electricity and Static Electricity Current ElectricityStatic Electricity amount of charge moving through a circuit build.
S1-3-09/10/12 Define electric current, voltage and resistance and solve related problems. KEY WORDS CellCoulombVoltage VoltVoltmeterCurrent AmpereAmmeterResistance.
Electrical Resistance and Ohm’s Law. The Electric Current  Electric current is a measure of the rate at which electric charges move past a given point.
Science 9 : Introduction to Current Electricity
Current Electricity.
Circuits & Electronics
Circuits Electric Circuit: a closed path along which charged particles move Electric Current: the rate at which a charge passes a given point in a circuit.
Solve for Z ABCDE HKMNP STVX WYZ =. Chapter 22 Current Electricity.
Do Now What work is required to move 7 coulombs of charge through a potential difference of 3 volts?
Introduction to Current Electricity, Part 1
Electric Circuits Recall: Terminal = electrode = +ve and –ve ends Metal component on cell that supplies electrons (-ve) or receives electrons (+ve) Must.
Circuits, Volts, Amps, and Resistance. Series circuits Simple circuits that have only one path for the current to flow are called series circuits.
Electric Current Electrical current is the flow of electrons. Unlike static electricity, charges are in motion. Two types of Current I. Direct current.
Electrical Potential (Voltage) Answers (Page 303)
Ch. 34 Electric Current.
 Water boy Water boy  Lightning Lightning  Team work Team work  Ac/Dc Charge Ac/Dc Charge.
Current Electricity. How is current produced? When a high potential is connected by a conductive material to a low potential. When a high potential is.
ELECTRIC CIRCUITS. I. Circuits A flow of electrons is called a current.  Symbol - I  Unit is Amperes or Amps (A)  I = q/t  Current is amount of charge.
CURRENT ELECTRICITY Characteristics of Current Electricity.
Amps, Volts and Resistance (Ohm’s Law). Coulomb  Recall that one Coulomb has 6.25 X electrons.  If the current coming out of the outlet on the.
(1)A source voltage, that is, an electron pump usually a battery or power supply. [ ENERGY IN] (2) A conductor to carry electrons from and to the voltage.
Ohm’s Law Conductor A conductor is a material that current can pass through easily, like metals.
ELECTRICAL CIRCUITS All you need to be an inventor is a good imagination and a pile of junk. -Thomas Edison.
Electric Current and Ohms Law. Electric Current The continuous flow of electric charge –The two types of current are direct current (DC) and alternating.
Electric Current and Resistance Physics. Potential Difference  Charges can “lose” potential energy by moving from a location at high potential (voltage)
Introduction to Current Electricity, Part 1 Grade 9 Academic Science R.H. King Academy.
ELECTRICAL COMPONENTS and CIRCUITS Instrumental Analysis II CTEC 1345.
Electrical circuits. Intensity (I): Number of charges that flow past a given point every second. Measured in Amperes (A). Wires that carry the electrical.
Electrical Resistance Electrical resistance is a measure of how difficult it is for electricity (electrons) to flow through a material. The units of resistance.
Current of Electricity Electric Current Potential Difference Resistance and Resistivity Electromotive Force.
Electric Current: Basics. Current Electricity Current electricity is like current in a river. A high or fast river current means the water is rushing.
Energy and Electrostatics. A new definition of potential energy An object has potential energy due to its location within a force field. To change the.
Resistance.
Electric Circuits. Electric Circuit Is a closed path for the flow of electrons. Consists of: 1.Source of electricity 2.Wires to conduct the flow of.
Electric Current, Resistance and Ohm’s Law
Electrical Circuits Making Electricity Useful Circuit Diagrams Electrical circuits can be shown in diagrams using symbols: 9.0V.
Electric Current. Electric Current (I) The net movement of electric charges in a single direction ▫Unit - amperes  Symbol – A  Measurement instrument.
Electricity and Circuit. Types of Electricity Static Electricity – no motion of free charges Current Electricity – motion of free charges – Direct Current.
Electric Current. Charge in motion (“flow” of charges). Charge in motion (“flow” of charges). Current: The number of electrons that pass a specific point.
Measuring Electricity. Electric Potential – the electrical energy that an electron possesses. Electric current is a measure of the rate at which the electric.
Amps, Volts and Resistance (Ohm’s Law)
8.3 – RESISTANCE AND OHMS LAW. SECTION 8.3 – RESISTANCE AND OHM’S LAW Resistance – is the property of any material that slows down the flow of electrons.
Current Electricity.
Aim: How do we determine the power in a circuit?
Recall that when two conducting objects at different potentials are connected by a conducting wire, charge flows from the object at a higher potential.
Electricity and Circuit
Introduction to circuits, Coulomb Law.
Voltage, Current, and Resistance
Electric Current: Basics
What are electric circuits?
Electric Current.
Check your Understanding
Characteristics of Current Electricity
Electrical Potential Joules units: = Volt = V Coulomb
ELECTRICAL CIRCUIT BOARDS
Current Intensity and Voltage
Topic H: Electrical circuits
Experiment No. 1 Ohm’s Law
REVISION CIRCUITS.
Please bring your book tomorrow.
Amps, Volts and Resistance (Ohm’s Law)
Ohm’s Law Page
Voltage Difference The difference in electrical potential between two places. Unit of measure = V (volts) Voltage causes current to flow through an electric.
Current Intensity and Voltage
Presentation transcript:

Current, Volts and Resistance (Ohm’s Law)

Coulomb Recall that one Coulomb has 6.25 X 1018 electrons. If the current coming out of the outlet on the wall has 600 C, how many electrons are coming out of the outlet? 1C = 6.25 X 1018 electrons 600 C #e- Cross multiply and you get 3.75 X 1021 electrons

Symbol: I Units: Amperes, A Current Intensity Current Intensity - the amount of electrons that flow past a given point in a circuit every second (i.e through a wire) Example: 0.7 amperes is shown by I = 0.7 A An ammeter is the instrument used to measure current intensity A

I = q/t Current Intensity The current intensity in a circuit can be determined using the formula: I = q/t I is the current intensity in amps (A) q is the charge in coulombs (C) t is time in seconds (s) NOTE: 1 Amp (A) = 1 Coulombs (C)/1 second (s) A=C/s

Example #1 What is the current flowing through a car headlight if there are 900 C of charge used in 1 minute? I = q/t I = 900 /60 I = 15A

Example #2 How much charge does it take to operate an MP3 player for 15 minutes if the current is 2A? I = q/t 2 = q/900 q = 1800C

Potential Difference (Voltage) Symbol: V Units: Volts, V Potential Difference (Voltage) Potential Difference is the amount of energy transferred between two points in an electrical circuit. It is the voltage that is measured at a load. Example: Energy that is provided by a battery or power supply. It could be a 12 volts battery (also know as 12V) A voltmeter is used to measure potential difference V

Potential Difference (Voltage) The potential difference can be determined using the formula: V=E/q V is potential difference in volts (V) E is the energy in joules (J) q is the electric charge in coulombs (C) Note: 1 Volts = 1 Joule / 1 Coulombs V=J/C

Example #3 In a house, how much energy is provided by 120V service providing 200C of charge? V=E/q 120 = E/200 E = 24 000J

Resistance Resistance is how difficult it is for current to flow Symbol: R Units: Ohms, Ω Resistance Resistance is how difficult it is for current to flow Resistance analogy: imagine a river flowing. If you put a large boulder in the river, the current on the other side of the boulder will slow down. If you put a small boulder in the river, the current on the other side of the boulder will still be quick. Now replace river flow with flow of electrons, and a boulder with a resistor. A resistor is used to slow current down and convert electrical energy into heat energy (e.g. light bulb, stove element). Resistor– high resistance & low current flow Conductor (wire) - low resistance & high current flow

Ohm’s Law Ohm’s Law states – that for a given resistance, the potential difference in an electrical circuit is directly proportional to the current intensity.

Formula to Solve Circuits Resistance, current intensity and potential difference are all related R = V/I R is the resistance in Ohm’s (Ω) V is the potential difference (Volts) I is the current intensity (Ampere) Note: 1 Ohms= 1 Volts / 1 Amper 1 (Ω) = 1 V / 1 A

Example #4 An stove element 30 Amperes going through it, and carries 120 volts of electricity, how much resistance is in this circuit? R = V/I R = 120 V/30 A R = 4 V/A = 4 Ω

Example #5 A circuit has a potential energy difference of 240 V and offers a resistance of 6Ω, what is the intensity of the current flow? R=V/I 6 = 240 /I I = 240 /6 I = 40 A

Example #6 A circuit has a resistance of 10Ω & a current intensity of 5A. What is the potential difference? R=V/I 10 = V/ 5 10 X 5 = 50V

Causes electrons to flow Summary Table Resistance Current Potential Difference Definition Slows current down The flow of electrons Causes electrons to flow Symbol R I V Units Ohms (Ω) Amps (A) Volts (V) Formula (if applicable) R=V/I Ω=V/I I=q/t A=C/s V=E/q V=J/C How measured Circuit Formula Ammeter or formula Voltmeter or formula

Assignment Page 319 – Questions 1 – 11 Handout