PHYS 012A Lecture Notes - Lecture 10: Field Line, Equipotential, Electric Potential
12 Jun 2018
School
Department
Course
Professor
Chapter 25: Electric Potential 10/2/17
Electric Potential
- When a test charge is placed in an electric field, it experiences a conservative force
- If the test charge is moved in the field by some external agent, the work done by the field is the
negative of the work done by the external agent.
Electron potential is a scalar characteristic of an electric field, independent of any charges that may be
placed in the field
The potential difference between two points exists solely because of a source charge and depends on
the source charge distribution
Voltage applies to a device or across a device is the same as the potential difference across the device
Electron volts – energy a charge-field system gains or loses when a charge of magnitude e is moved
through a potential difference of 1 volt. 1 ev = 1.60 *10-19 J
Electric field lines always point in the direction of decreasing electric potential.
find more resources at oneclass.com
find more resources at oneclass.com
Energy and the Direction of Electric Field
- When the electric field is directed downward, point B is at a lower potential than point A.
- When a positive test charge moved from A to B, the charge-field system loses potential energy
- Electric field lines always point in the direction of decreasing electric potential
Electric field goes from high potential to low potential
- Electric force goes from high potential energy to low potential energy as well.
Equipotential: the name equipotential surface is given to any surface consisting of a continuous
distribution of points having the same electric potential. Points in a plane perpendicular to a uniform
electric field are at the same electric potential.
find more resources at oneclass.com
find more resources at oneclass.com
High potential → → → Low potential
But if it is a negative then it will increase in electric potential but move from higher potential to lower
potential
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
When a test charge is placed in an electric field, it experiences a conservative force. If the test charge is moved in the field by some external agent, the work done by the field is the negative of the work done by the external agent. Electron potential is a scalar characteristic of an electric field, independent of any charges that may be placed in the field. The potential difference between two points exists solely because of a source charge and depends on the source charge distribution. Voltage applies to a device or across a device is the same as the potential difference across the device. Electron volts energy a charge-field system gains or loses when a charge of magnitude e is moved through a potential difference of 1 volt. When the electric field is directed downward, point b is at a lower potential than point a.
