Physics and Math Chapter 5: Electrostatics and Magnetism Flashcards
What is the SI unit of charge?
The coulomb
What is the fundamental unit of charge?
e = 1.6 x 10^-19 C
What are conductors?
They allow the free and uniform passage of electrons when charged.
What are insulators?
Resist the movement of charge and will have localized areas of charge that do not distribute over the surface of the material.
What is Coulumb’s law?
Gives the magnitude of the electrostatic force vector between two charges. The force vector always points along the line connecting the centers of the two charges.
What does every stationary charge generate?
an electric field, which can exert forces on other charges
What is the electric field?
the ration of the force that is exerted on a test charge to the magnitude of that charge.
Where will positive test charges move? negative?
+ –> direction of the field lines
- –> opposite direction of the field lines
What is electrical potential energy?
The amount of work required to bring the test charge from infinitely far away to a given position in the vincinity of a source charge.
When will the electrical potential energy of a system increase?
When 2 like charges move toward each other or when two like charges move further apart.
When will the electrical potential energy decrease?
When the two opposite charges move toward each other or when two like charges move further apart.
What is the electrical potential?
The electrical potential energy per unit charge.
What is potential difference/voltage?
the change in electrical potential that accompanies the movement of a test charge from one position to another.
What is the unit for electrical potential and voltage?
Volts
Two things about the potential difference
Path independent and depends only on the initial and final positions of the test charge.
Where will test charges move?
Spontaneously in whichever direction results in a decrease in their electrical potential energy
Where will positive test charges move spontaneously? negative?
+ From high potential to low potential.
- From low potential to high potential.
What are equipotential lines?
They designate the set of points around a source charge or multiple source charges that have the same electrical potential.
What are equipotential lines?
designate a set of points around a source charge or multiple source charges that have the same electrical potential.
- always perpendicular to electrical field lines.
When will work be done with equipotential lines?
when a charge is moved from one to another. It is independent of the pathway taken between the lines. No work is done when a charge moves on the same equipotential line
What generates an electric dipole?
Two charges of opposite sign separated by a distance
What does torque have to do with it?
In an external field, an electric dipole will experience a torque until it is aligned with the electric field vector.
what is a magnetic field?
Created by magnets and moving charges.
What is the SI unit for the magnetic field?
Tesla
What is a diamagnetic material?
possess no unpaired electrons and becomes weakly magnetic in an external magnetic field
What is a paramagnetic material?
Possess some unpaired electrons and become strongly magnetic in an external magnetic field.
What are ferromagnetic materials?
Possess some unpaired electrons and become strongly magnetic in an external magnetic field.
Where do field lines point in a magnet?
From the north to the south pole
What is the lorentz force?
the sum of the electrostatic and magnetic forces acting on a body.
