All Flashcards
What is the effect of inserting a dielectric into a capacitor?
It increases the capacitance by allowing more charge to be stored at the same voltage and reduces the electric field strength.
What is the effect of polarization of dielectric molecules?
Creates a layer of opposite charge on the surface, attracting more charge onto the capacitor plates, increasing capacitance.
What happens to the electric field when a dielectric is inserted?
The overall electric field between the plates is weakened due to the induced electric field within the dielectric.
What happens to the voltage when a dielectric is inserted at constant charge?
The voltage is reduced because V = Ed, and the electric field (E) is reduced.
What happens to capacitance when voltage decreases at constant charge?
Capacitance increases, because C = Q/V.
Compare the electric field with and without a dielectric.
Without dielectric: Stronger electric field. | With dielectric: Weaker electric field due to polarization.
Compare the capacitance with and without a dielectric.
Without dielectric (): Lower capacitance. | With dielectric (): Higher capacitance.
Compare the potential difference with and without a dielectric (capacitor disconnected from battery).
Without dielectric: Higher potential difference. | With dielectric: Lower potential difference.
Compare the energy stored with and without a dielectric (capacitor disconnected from battery).
Without dielectric: Higher energy stored. | With dielectric: Lower energy stored.
Compare the electric field induced within the dielectric vs. the overall electric field between the plates.
Induced electric field: Reduces the overall field. | Overall electric field: Determines the voltage and capacitance.
In the Dielectric Polarization diagram, what does the alignment of molecules in the dielectric create?
A layer of opposite charge on the surface.
In the Dielectric Polarization diagram, what happens to the electric field lines within the dielectric?
Some field lines end on the charges within the dielectric, weakening the overall electric field.
In the Cylindrical Capacitor diagram, what is the charge on the inner cylinder?
+Q
In the Cylindrical Capacitor diagram, what is the charge on the outer cylinder?
-Q
In the Cylindrical Capacitor diagram, what fills the space between the cylinders?
Oil with a dielectric constant k.