QUICK WRITE: For 2 minutes, write the three parts of an atom and what their charges are. Explain what creates an electric charge (positive or negative) on something. Rules - You MUST write for the entire time, even if you write the exact same thing over and over again!
Protons = Charge Electrons = Charge Neutrons = Charge When Protons = Electrons, atoms are said to be ELECTRICALLY NEUTRAL (no net charge)
At your table, determine whose First Name comes LAST in the alphabet. That person will talk first! Each person will get 20 seconds to talk and MUST talk the WHOLE TIME. I will signal when each person should start and stop. Person 1: Compare/Contrast Insulators and Conductors Person 2: Which would you want in your coffee mug and why? Which would you want inside your phone charger and why?
Conductors and Insulators Conductors objects in which electrical current easily passes through such as metals and graphite Insulators objects that resist the flow of electrical current such as plastic, wood, paper, and rubber
Where is the conductor in these pictures? How do you know?
Where is the insulator in these pictures? How do you know?
The flow of ELECTRONS through a conductor: Electrons flow from the negative end of the battery to the positive end of the battery (Current/Electricity flows from the positive end of the battery to the negative end of the battery)
Factors that affect Force 1. Distance between the charges 2. Amount of charge
SI Unit of charge is Coulomb [C]
What do these two pictures have in common? Talk with your partner for 30 seconds and BE PREPARED TO SHARE!
The accumulation of excess electric charge. (not balanced) Ex. Lightning
https://www.youtube.com/watch?v=hpij3czurpq&feature=youtu.be Quick Write: Which is stronger electric force or gravitational force? How do you know? Be prepared to be called on! :O
The correct answer should be the Electric Force! Like you witnessed in the video the electric force can overcome the gravitational pull of the Earth; and the Strong Electric Force is responsible for holding together the protons and neutrons in the nucleus of an atom.
Which of the following objects is a good conductor? A. Pure Water B. Rope C. Copper D. Plastic
Which type of force is strongest? A. Gravitational force B. Electrical Force
Which of the following balloon configurations depict the correct charges of the balloon and wall?
An imbalance of electrical charge is also known as: A. Charged electricity B. Static Electricity C. Contact Electricity D. Negative Electricity
ELECTRICAL CIRCUITS
What is this a picture of? - + Pay Attention to the direction before you answer!
What is electric current? Electric Current (I) - flows from the (+) terminal to the (-) terminal of a cell/battery through wires and components - + Do NOT confuse this with the flow of ELECTRONS which go from the negative end to the positive end of the battery!!!!
Electric Field Electric Field when the electrons of a current are in motion, lines of electric force rotate around the electron, or between two charges.
Does your picture provide Light or No Light? Do you know WHY?
Open and Closed Circuits Open circuit = switch is open = no current is flowing = bulb does not light Closed circuit = switch is closed = current is flowing = bulb lights up
Circuit Diagram & Symbols Cell/Battery Light Bulb Wires Resistor Light Bulb Resistor Switch
Draw a picture of a SERIES Circuit. Show a battery and a light bulb in your drawing. Draw a picture of a PARALLEL Circuit. Show a battery and TWO light bulbs in your drawing. Be prepared to discuss your pictures.
Types of Circuits Series Circuits current takes only one path and is the same at each point. (One Wire connects ALL)
Series Circuits If one bulb blows out, it breaks the circuit and all the bulbs go out If you add more cells/batteries to a series circuit, the bulbs burn brighter
Types of Circuits Parallel Circuits current takes more than one path and is NOT the same at each point. (Multiple Wires)
Parallel Circuits If one bulb blows out, there is still another complete circuit for the other bulb to stay lit
Draw these circuits in your Notebook. Label each one as either Series or Parallel. A Parallel B Series
Conductor or Insulator? Conductor
Brighter or Dimmer? Dimmer
Series or Parallel? Series
Brighter or Dimmer? Brighter
Series or Parallel? Parallel
Series or Parallel? Series
Series or Parallel? Parallel
Ohm s Law
Ohm s Law
What happens to the Resistance when the Current is doubled and the Voltage stays the same? The Resistance is halved!
What will happen to the Voltage when the Resistance is tripled and the Current remains constant? The Voltage is Tripled too!
What happens to the Current when the Resistance is reduced by 1/3 and the Voltage stays the same? The Current is Tripled!
Measuring Current Current is measured in units of amperes (A) 2A 2A 2A 2A 2A In a series circuit, current is the same at all the points 1A 1A In a parallel circuit, current is shared between all the points
What is the current? 4A 3A 1A 3A 4A 4A 1A 1A SERIES CIRCUIT PARALLEL CIRCUIT
Measuring Voltage Voltage the electrical push that a cell/battery gives to the current Voltage is also known as Potential Difference Voltage is measured in units of volts (V)
Measuring Voltage 3V 3V 3V 1.5V 1.5V 3V In a series circuit, voltage is shared between all the points In a parallel circuit, voltage is the same at all the points
What is the current and voltage? 4A 6V 4A A 3V V 3V V 4A A Current Voltage Series Same Shared Parallel Shared Same
What is the current and voltage? 4A 6V 4A A 6V V 2A A 6V V 2A A
Measuring Resistance Resistance slows down current, adding components to a circuit increases resistance Resistance is measured in units of ohms (Ω) More resistance = Less current = Less light In a series circuit, add up all resistance to get total.
Electrical Power
How much voltage gives 5 amps of current through a 3 Ω light bulb? I = V/R V = (5A) (3Ω) V = 15V
How much current flows in a circuit with a 1.5 volt battery and three 1 ohm resistances (bulbs) in series? I = V/R I = (1.5V) / (3Ω) I =.5A
What is the voltage drop across each resistor in the circuit? In a series circuit, voltage is shared between all the points 9V/3 = 3V
A light bulb with a resistance of 1.5Ω is connected to a 1.5V battery in the circuit. Calculate the power used by the light bulb? P = IV I = V/R I = (1.5V) / (1.5Ω) I = 1A P = (1A) (1.5V) = 1.5 W P = 1.5 W