6.2 Electric Fields Flashcards
What is a Field?
A region where a force is exerted on an object at a distance. Electric fields are created by charged particles and exert a force on charged particles.
Define Electric Field Strength
The force per unit positive charge
What are the Patterns of Electric Fields?
• Always start on a positive charge and end on a negative
• Electrons, protons and other charged particles are treated as point charges
How does the Closeness of Electric Field Lines related to Electric Field Strength?
The closer the field lines are together the stronger the electric field. Field lines can’t touch or cross.
Define Coulomb’s law
The force between two charges is proportional to the product of the charges and inversely proportional to the square distance between the charges
What is the Permitivity of Free Space (ε°)?
The degree to which a medium resists the flow of electric charge (8.85x10^-12)
What happens to a Charged Particle in a Uniform Electric Field?
Charged particles will be accelerated by the field, the gain in Ek is equal to the work done in moving the charge through the distance between the plates
What Shape of Field do Point Charges have?
A radial field
What do Field Lines Show?
The path a positive test charge takes in an electric field (from + to -)
What can the Motion of Charged Particles in an Electric Field be Modelled as?
Projectile Motion (the two components of velocity are independent of each other)
Velocity perpendicular to the field isn’t effected, velocity parallel to the field is
How do you Calculate the Parallel Component of Velocity in an Electric Field?
1) Calculate the time the particle is in the field (time = d/s) d = plate length s = perpendicular velocity
2) Use F =ma and F = Eq for a = (Eq)/m
3) Sub these values into V = u + at where u is the initial parallel velocity and v is the final parallel velocity
What does the Force/Distance Graph look like for a Point/Spherical Charge?
y = 1/x when x>0
What does the Area under a Point/Charge Force/Distance Graph Represent?
The work done in moving the charge
What is the Formula for Electric Energy near a Point Charge
E = Vq
