Download Electrical Potential Guided Notes Name: Just as masses can have

Electrical Potential Guided Notes
Name:______________________
Just as masses can have gravitational potential energy, charges can have electrical potential energy
How can a mass or charge gain potential energy? ________________________________
Does the amount of work done by the monkey change if the charge changes? How do we know?
What does this imply about electrical potential energy?
Electrical Potential and Electrical Potential Energy
Introducing … Electrical Potential (V) … a measure that depends only on ___________________, not on ___________.
The SI unit of electrical potential is the volt
Note important difference between energy and potential:
•
A ______________________ has ________________, a _______________ placed there has
___________________________
•
Two points that are at the same distance from the charged object have the same potential.
•
So, when two charged objects are placed there, they are at the same potential, but the one with more charge on
it has higher electric potential energy. It is harder to push it there.
The quantity electric potential is defined as the amount of _____.
1. electric potential energy
2. force acting upon a charge
3. potential energy per charge
4. force per charge
What happens if a positive charge is moved from point A to point B?
Potential Difference ΔV
The potential difference between two points is exactly what the name implies – the
______________________________ between two points.
The change in electric potential energy between two points also equals the ____________________________________
in order to move it from one point to the other.
Potential Difference (ΔV) & Circuits
What is the role of a battery in a circuit?
Batteries supply the _________________________ to maintain the
________________________________ across a circuit
1) A 12V battery means that the _______ terminal has an ____________________ that is 12V higher than the –
terminal.
2) Charges flow through the external circuit (the wire) from high to low potential.
3) As the charges flow through the circuit, they ‘lose’ energy to circuit elements such as lights and motors
4) By the time the charges get to the end terminal, they have used up 12 V of potential
5) The battery supplies the _________________________________________________________________
As charges ‘lose’ energy to different circuit elements, the electric potential decreases. This is known as voltage drop.
All of the electric potential difference– i.e. all of the voltage -- is used up by the end of the circuit.
Terminology Fun
1. The variable we use for potential, potential difference, and the unit for potential difference (volts) is V.
2. Don't let that confuse you when you see V = 1.5V
3. Electric potential energy is not the same as electrical potential.
4. The electron volt is not a smaller unit of the volt, it's a smaller unit of the Joule.
5. Electrical potential can also be described by the terms, potential difference, voltage, voltage drop, potential
drop, potential rise, electromotive force, and EMF. These terms may differ slightly in meaning depending on the
situation.
You Do Problems
1.
Compare an electric circuit to a roller coaster ride.
What is the difference in height from the top to the bottom of a rollercoaster analogous to in a circuit?
What is the motor that pulls the rollercoaster up the hill analogous to in circuit?
2.
If a battery provides a high voltage, it can ____.
a. do a lot of work over the course of its lifetime
b. do a lot of work on each charge it encounters
c. push a lot of charge through a circuit
d. last a long time
3.
Compared to point D, point A has …
a. 12 V higher potential energy
b. 12 V lower potential energy
c. Exactly the same potential energy
4.
The electrical potential energy is 0 at …
a. A
b. B
c. C
d. D
5.
Energy is required to move a charge from…
a. Point A to point B
b. Point B to point C
c. Point C to point D
d. Point D to point A
6. The energy required to move +2C of charge from D to A is
a. 1. 0.167 J
b. 2. 2 J
c. 3. 6 J
d. 4. 24 J
7.