Physics Flashcards
What are the properties of charge?
- Like charges repel
- Opposite charges attract
- Charge is strictly conserving, mean net q is constant
- There is short range interaction.
What are conductors?
A material in which charge moves freely.
What are insulators?
A material in which charge cannot move.
What are the properties of electric fields?
- The total electric field from two charges is the sum of E(total) = E1+E2
- The electric field due to a positive charge points away from it
- The electric field due to a negative charge points toward it.
- An E-field exists whether or not there’s a test charge to feel it.
- The value of the electric field is independent of its test charge.
- F = qE; E = F/q
Kerchoff’s Loop Law
- Total charge in the electric potential across the loop (entire circuit) should be zero.
- Work is dependent on the point charge.
What is the electric field?
The electric force per test charge due to a charge configuration.
1. Point Charge: E = (kq/r^2)r(hat)
What is a dipole?
A vector that points from the negative charge to the positive charge.
What happens during a pure dipole moment?
The total charge on the system is zero.
What are the properties of conductors?
- Charge flows freely
- Electric field inside conductor is equal to zero.
- The electric potential is constant.
- Any excess charge is on the surface.
- Exterior electric field is perpendicular to the surface.
What is a the formulas for conducting spheres?
E=(kQ/r^2)r(hat)
V=kQ/r
F=(kQ1Q2/r^2)r(hat)
What is the electric field formula for conducting plates?
E=(sigma/2epislonnaught)n(hat)=(Q/2Aepsilonnaugt)n(hat)
What is the electric field formula for parallel plate capacitors?
E(inside) = (sigma/epsilonnaught)x(hat)
E(outside)=0
What are the model systems?
Point charges and electric dipoles
What are the 4 graphical representations of the potential?
Potential graph
Equipotential surfaces
Contour Map
Elevation Graph
What is the formula for dipole moment?
p=qs
