8.3.2 - Electric Current & Simple Circuits

Multiple Choice

What charge does a proton have?

• negative (-)
• positive (+)
• neutral or no charge (0)

Let's recall last lesson.

• Static electricity is the buildup of electric charges.

• Opposite charges attract; like charges repel.

• Positively charged atoms have more protons

• negatively charged atoms have more electrons.

Multiple Choice

What charge does an electron have?

• negative (-)
• positive (+)
• neutral or no charge (0)

Multiple Choice

Static electricity is 

• The balance of electrical charge on an object
• The imbalance of electrical charge on an object
• The discharge of electrical charge
• The build up of protons in the nucleus of an atom 

During a lightning...

• Electrons in the atmosphere jump down to pair with protons on the ground.

• 
  

• 
  

• 
  

electric currents

What is an electric current?

The flow of electric charges through a conductor.

The difference between static electricity and electric currents.

Electric charges that build up on static electricity do not flow. Instead the charges jump between two objects.

electric currents is a flow of electrons like a stream of water through a conductor like copper or metal.

Electric Current

• When Electric charges are made to flow through a material, they produce an electric current

• An electric current is the continuous flow of electric charges through a material

• The amount of charge that passes through a wire at a given period of time is the rate of electric current

• The unit for the rate of electric current is the Ampere (A)

Multiple Choice

__________________ is the continuous flow of electric charges through a material.

• Electric current
• Resistance
• Voltage
• Static Discharge

Multiple Choice

What is current measured in?

• Ω (Ohms)
• V (Volts)
• A (Amps)
• W (Watts)

Multiple Choice

Current is...

• moving protons
• moving electrons
• measured in volts
• measured in ohms

Multiple Choice

Metals such as copper and aluminum are good ______________. 

• insulators
• conductors
• circuits
• charges

Multiple Choice

______________ are materials such as rubber that do not allow charges to flow.

• conductors
• circuits
• insulators
• amps

Multiple Choice

Electric current is ___________

Electricity moves in currents

• Current is the flow of electrons from

  one place to another.

• Measured in amperes (amps)

• A form of kinetic energy

Multiple Choice

Electricity that moves is...

• potential energy

• kinetic energy

Electricity

Section 2

Electrical Resistance
〉 What causes electrical resistance?

〉 Resistance is caused by internal friction,

which slows the movement of charges
through a conducting material.

• resistance: the opposition presented to the current

by a material or device

Multiple Choice

resistance is caused by

• Gravity

• Temperature

• friction

• Pressure

Multiple Choice

What is the unit for Resistance?

• Ohms

• Volts (V)

• amps (A)

Electricity

Voltage and Current

• Current is the rate of charge movement.

– electric current: the rate at which charges pass

through a given point

– The SI unit of current is the ampere, A.

• 1 amp = 1 C/s

Multiple Choice

The rate at which a charge passes through given point is

• Voltage

• current

• Resistance

• Power

Electricity

Section 2

Voltage and Current

• In a direct current source the charges always move from

one terminal to the other in the same direction.

– example: battery

• Conventional current is the current made of positive

charge that would have the same effect as the actual
motion of charge in the material.

– The direction of current is opposite to the direction

that electrons move.

Electricity

Section 2

Electrical Resistance
〉 What causes electrical resistance?

〉 Resistance is caused by internal friction,

which slows the movement of charges
through a conducting material.

• resistance: the opposition presented to the current

by a material or device

Multiple Choice

What is current measured in?

• Ω (Ohms)
• V (Volts)
• A (Amps)
• W (Watts)

Multiple Choice

What is voltage measured in?

• Ω (Ohms)

• V (Volts)

• A (Amps)

• W (Watts)

Multiple Choice

If the Voltage is increased and the resistance stays the same, Current will

• Increase
• Decrease
• Stay the same
• X

Multiple Choice

Electricity that flows in a closed path is called a

• path
• current
• circuit
• light

Multiple Choice

To complete a circuit the switch must be

• unattached
• open
• closed
• It depends

Multiple Choice

What is Resistance?

• The flow of electrons
• Electric potential difference
• A battery
• The ability to reduce the flow of electrons

Multiple Choice

What is resistance measured in?

• Ω (Ohms)
• V (Volts)
• A (Amps)
• W (Watts)

Multiple Choice

If the Voltage stays the same and Resistance is increased, Current will 

• Increase
• Decrease
• Stay the same
• X

Multiple Choice

The mathematical relationship among Voltage, Current, and Resistance

• Faraday's Law
• Tesla's Law
• Edison's Law
• Ohm's Law

Multiple Choice

Current times Resistance equals what?

(I X R)

• Power

• Voltage

• Amperage

• Ohm

Multiple Choice

Voltage divided by Resistance equals?

(V / R)

• Current

• Power

• Ohms

• Watts

Multiple Choice

What size resistor would produce a 3 Amp current flow with a 12 Volt battery

• 1 Ohm
• 3 Ohms
• 4 Ohms
• 12 Ohms

Multiple Choice

What is the Voltage of a circuit that has a resistance of 5 Ω and a current of 2 A?

• 25 V
• 10 V
• 2.5 V
• 0.4 V

Multiple Choice

How many Volts would we need to produce a current flow of 8 Amps through a 6 Ohm resistor

• 12 volts
• 24 volts
• 1.3333
• 48 volts

Multiple Choice

This circuit has a 24 volt battery and the resistor is 8 ohms. How many amps are running through the circuit?

• 3 Amps
• 192 Amps
• 2 Amps
• 4 Amps

Multiple Choice

What size resistor would produce a 3 Amp current flow with a 12 Volt battery

• 1 Ohm
• 3 Ohms
• 4 Ohms
• 12 Ohms

Multiple Choice

What would the circuit resistance be if a 7.5 Amp draw was present with the engine running and the charging system producing 15 Volts

• 15 Ohms
• 4 Ohms
• 0.3333 Ohms
• 2 Ohms