Chapter 23 - Electric Current Flashcards
What is Potential Difference?
Potential difference is the difference in electrical potential between two points.
What is interchangeable with Potential Difference?
Voltage Difference!
When does charge flow?
Charge flows when there is a difference in electric potential. As soon as the ends/points are equal, there will be no more flow of charge.
What is Electric Current?
Electric current is the flow of electric charge.
What do conduction electrons do? Why?
Conduction electrons carry charge. They do this because they are free to move throughout the atom.
Do protons carry charge like conduction electrons?
NO! Protons are tightly bound to the nucleus.
What is the unit for electric potential?
Volts (V).
What is the voltage for a common automobile battery?
12 Volts.
What produces current?
Voltage produces current in a complete circuit.
Why does charge flow through a circuit?
Charge flows through a circuit because voltage is applied across the circuit.
What is the unit for Electrical Resistance?
Ohms (Ω).
What is the relationship between Resistance and Temperature? Resistance and Conductivity?
Higher temperature means higher resistance.
Higher conductivity means lower resistance.
What does Ohm’s Law state?
Ohm’s Law states that current is directly proportional to voltage and inversely proportional to resistance.
What is the equation for Ohm’s Law?
Current (I) = Voltage (V)/Resistance (Ω).
What is the range for Electrical Resistance in a person’s body? What is the state of the body at each?
100 Ω (very WET) to 500,000 Ω (very DRY).
What do Resistors do?
Resistors regulate current.
What happens when you grab an electric wire with your hand?
Your fingers contract over the wire! They are NOT attracted to the wire. This means you cannot pull your hand away.
Why can a bird stand on an electrical wire without experiencing electric shock?
Birds can stand on electrical wires because there is no difference in electric potential!
What must exist in order for you to experience electric shock?
There must be a difference in electric potential.
What is Direct Current?
Direct current (dc) is when charge flows in one direction.
What is Alternating Current?
Alternating current (ac) is when charge flows in one direction, then the opposite, then alternates.
What is a Diode?
A diode is a device that allows electrons to only flow in one direction.
Why do electrons in room temp. metals not produce current?
They don’t produce current because they are moving in all possible directions. There is no net flow in any direction.
What is Drift Velocity?
Drift velocity is the net flow of electrons. It is extremely slow.
Do electrons or energy flow from an outlet to a lamp?
ENERGY! Electrons already exist in the lamp when the energy flows to it.
What is the equation for Electric Power?
Electric Power (Watts) = Current (I) x Voltage (V).
What is Electric Power?
Electric power is the rate that electric energy is converted into another form. Ex.) mechanical energy, light energy, etc.
What is a Circuit?
A circuit is any path that electrons can follow/flow through.
What is a Series Circuit? How are devices connected?
A series circuit is a single pathway for electrons to flow.
Devices are along the same path and if one goes out, so will the rest.
What is a Parallel Circuit? How are devices connected?
A parallel circuit has branches of paths for electrons to flow.
Devices are independent of each other.
What is an Open Circuit?
NO flow.
What is a Closed Circuit?
Free passage of electrons.
