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what kind of quantity is Electric field strength?
a vector quantity
the Lines of electric force
Capacitor dielectrics are usually what kind of material
insulators
What is the shape of an electric field?
it is a three-dimensional shape expanding outward in the shape of the charged object
What unit is used to describe Electrical potential energy?
Joules
in which direction do electric field lines of force point?
What is the charge of the test charge in the electric field model
always small and positive
The SI unit of capacitance is the
farad
Which of the common states of matter is tend to have the lowest dielectric constant?
Name two devices used for storing electrical charge (not a battery)
a capacitor and the Leyden Jar
What is electric field strength?
the force per unit charge at each point in the field
(analogous to the acceleration of gravity; think the "acceleration" of electric attraction/repulsion)
The work required while moving a point charge of any size from one location in an electric field to another equates to the ___________ between those two locations.
difference in electrical potential energy
How would you make a capacitor that would have more capacitance, one with the plates closer together or further apart?
closer together
What is the capacitance of three 7.0 μF connected in parallel?
21 μF
If a capacitor has a large dielectric constant, will its capacitance be larger or smaller than a capacitor with a smaller dielectric constant
larger, when it comes to capacitance, a better insulator with a higher dielectric constant will hold the charge better
Capacitors with a vacuum dielectric (κ=1) will have a greater or smaller potential difference than the same capacitor with the dielectric replaced with paper (κ= 3.7)?
vacuum would have a greater potential difference
Vdie=V0/κ
Describe at least two attributes of electric lines of force in the electric field model.
lines of force point toward negative charges
the closer the lines of force, the stronger the electric field
field lines never cross
Define equipotential surface
the area around a charged object at which moving along it would result in no change in potential energy, and thus no work being accomplished
think of it like a thin shell of 3D curving flat space
What is a capacitor (what are its parts)
conducting plates separated by an insulating material called a dielectric
What would happen to the charge distribution on a charged capacitor if the electrical connections to the capacitor changed polarity after it was already charged?
The charges on each plate would decrease as the charge on the capacitor was drawn off by the opposite polarity of the circuit.
A point charge of 15.0 x 10-5 C in an electric field experiences a force of 0.120 N. what is the magnitude of the field strength?
E=F/q
E = 800 N/C
Calculate the capacitance of a capacitor with plates 0.5 m2 separated by 0.0015 m paper dielectric (κ = 3.7) (ε0 = 8.854 × 10–12 C2/N⋅m2)
1.09 x 10-8
What is the magnitude of the charge on each plate of a capacitor with a capacitance of 1.1 x 10-8 F connected to a 12 V battery?
1.32 x 10-7 C
What is the capacitance of five 7.25 μF capacitors connected in series
1.45 μF
For more than 2 in series: 1/Ctotal=1/C+1/C+1/C+. . .
Describe how a classical Leyden Jar works
The Leyden jar consists of a glass jar which has a coating of lead inside and out but is separated by the glass wall. A conducting rod passes through an insulated stopper. A metal chain connects the conducting rod and the inner lead coating. When a charge is applied to the conducting rod, the charge passes to the inner coating. This polarizes the glass wall, inducing an opposite charge on the outside of the jar, which can be grounded. When the ground path is broken and the charge is removed, the charge is stored in metal coatings of the Leyden jar