Using the materials provided to your group…

See if you can make the light bulb light in 4 different ways.

You have 5 minutes!!!MIT graduates attempt...

CIRCUIT CHALLENGE

MIT graduates attempt...

• In current electricity, electrons are continuously moving; different from static

• Because the charges are flowing (moving), they have the ability to do work

+

Electrons flow in a

circular path from

positive to

negative

•Source of electric energy (battery or wall outlet)

•Wires•Device that uses the energy (light bulb, etc.)

Resistor

Any object that uses the energy

Voltmeter

Measures voltage between 2 points, placed in parallel, very high resistance

Ammeter

Measures current, placed in series, very low resistance

A1

Battery

Energy source

Light bulb

Wire

A conductor that provides a path for the electrons to travel along

Switch

Controls whether the circuit is open or closed

V1

• In order for electricity to move through a circuit it must be closed

• If a circuit is open then the electricity cannot flow

• Switches are objects that are used to determine whether a circuit will be closed or opened

http://phet.colorado.edu/new/simulations/sims.php?sim=Circuit_Construction_Kit_DC_Only

open

“For a given resistance, the voltage is proportional to the

current flow.”

Voltage (Volts)

Current (Amps)

Resistance (Ohms

or Ω)

“Describes the relationship between Voltage, Current & Resistance”

• Def : the energy each electron has to move it through a circuit to do work• Unit: Volts (V)• Symbol: V

= 1.5 volts

3.0V?V

If

6 V

• Def : the number of electrons passing a point per second in a circuit; “Rate of flow”

•Unit: Amperes (amp)•Symbol: I• It is measured using an ammeter

A

• Resistance is the opposition to the flow of charge

Ω

Symbol: (R)Unit: ohm (Ω) Measured by an

ohmmeter

“For a given resistance, the voltage is proportional to the

current flow.”

Voltage (Volts)

Current (Amps)

Resistance (Ohms

or Ω)

“Describes the relationship between Voltage, Current & Resistance”

Questions:• Sample problems:• A fluorescent light draws 0.25 amps of current

when connected to a 120 V source. What is the resistance of the light?

• What voltage is needed to cause a current of 50 amps through a resistance of 20 ohms?

• What happens if we have two or more light bulbs connected?

Mini-Project: Due Before Final• Students in Mr. Penmoon class just happened to

be nominated to work with the Lord of the Ring team for the up coming season in ‘’the land of the lord of the ring” where there is no electricity.

• Our task is to use our knowledge to help them harvest the energy from the sun. “Concept of Photoelectric Effect”

• We need to come up with the plan. We need to know how much energy is needed daily for work. And what type of circuit (series or parallel) to implement for the most efficient.

http://phet.colorado.edu/new/simulations/sims.php?sim=Ohms_Law

Voltage (Volts)

Current (Amps) Resistanc

e (Ohms or Ω)

What is the voltage of this battery?

4.5 V