Properties of Capacitors and Dielectrics - AP Physics 2
Card 0 of 6
Fill in the blanks.
Dielectrics __________ capacitance because capacitance is __________ related to electric field strength, and dielectrics __________ effective electric field strength.
Fill in the blanks.
Dielectrics __________ capacitance because capacitance is __________ related to electric field strength, and dielectrics __________ effective electric field strength.
The reason dielectrics reduce the effective electric field strength is because when a dielectric is added, the medium gets polarized, which produces an electric field in opposition of the existing electric field.
When the electric field decreases, the capacitance increases because the plates are able to store more charge for the same amount of voltage applied, because there's less force repelling electrons from gathering on the plate.
The reason dielectrics reduce the effective electric field strength is because when a dielectric is added, the medium gets polarized, which produces an electric field in opposition of the existing electric field.
When the electric field decreases, the capacitance increases because the plates are able to store more charge for the same amount of voltage applied, because there's less force repelling electrons from gathering on the plate.
Compare your answer with the correct one above
Two parallel conducting plates separated by a distance 
are connected to a battery with voltage 
. If the distance between them is doubled and the battery stays connected, which of the following statements are correct?
Two parallel conducting plates separated by a distance
The equation for capacitance of parallel conducting plates is:
When the distance is doubled, the capacitance changes to:
The battery is still connected to the plates, the potential difference is unchanged. Because 
, and the capacitance is halved while the voltage stays the same, 
must necessarily drop to half to account for the change.
The equation for capacitance of parallel conducting plates is:
When the distance is doubled, the capacitance changes to:
The battery is still connected to the plates, the potential difference is unchanged. Because
Compare your answer with the correct one above
A dielectric is put between the plates of an isolated charged parallel plate capacitor. Which of the following statements is true?
A dielectric is put between the plates of an isolated charged parallel plate capacitor. Which of the following statements is true?
When a dielectric is added to a capacitor, the capacitance increases. In our problem, it says the system is charged and isolated, which means no charge will escape the system. Therefore the charge on the plates will stay the same.
The equation for capacitance is:
Since the charge stays the same, and the capacitance increases, the potential difference must decrease so that 
may increase.
When a dielectric is added to a capacitor, the capacitance increases. In our problem, it says the system is charged and isolated, which means no charge will escape the system. Therefore the charge on the plates will stay the same.
The equation for capacitance is:
Since the charge stays the same, and the capacitance increases, the potential difference must decrease so that
Compare your answer with the correct one above
Capacitances are as follows:
What is the total capacitance of the system in the diagram above?
Capacitances are as follows:
What is the total capacitance of the system in the diagram above?
Recall the equations used for adding capacitors:
From the diagram, capacitors A and B are in parallel, and capacitors C and D are in parallel, and those two systems are in series.
Use the equation above to find the equivalent capacitance of capacitors A and B.
Use the equation above to find the equivalent capacitance of capacitors C and D.
Use the equation above to find the total capacitance by adding the two systems of capacitors, which are in series.
Therefore, the total capacitance is 
Recall the equations used for adding capacitors:
From the diagram, capacitors A and B are in parallel, and capacitors C and D are in parallel, and those two systems are in series.
Use the equation above to find the equivalent capacitance of capacitors A and B.
Use the equation above to find the equivalent capacitance of capacitors C and D.
Use the equation above to find the total capacitance by adding the two systems of capacitors, which are in series.
Therefore, the total capacitance is
Compare your answer with the correct one above
Capacitances are as follows:
Consider the diagram above. If the battery has a potential difference of 
, what is the total energy of the system once it's fully charged?
Capacitances are as follows:
Consider the diagram above. If the battery has a potential difference of
The equations for adding capacitors are:
To find the total energy, we need to know the total capacitance. To do that, we the capacitors together according to the rules above.
Capacitors A and B are in parallel.
Capacitors C and D are in parallel.
Add the systems of capacitors together. They are in series.
The total capacitance is 
The equation for finding the energy of a capacitor is:
Plug in known values and solve.
Therefore, the system, when fully charged, holds 
of energy.
The equations for adding capacitors are:
To find the total energy, we need to know the total capacitance. To do that, we the capacitors together according to the rules above.
Capacitors A and B are in parallel.
Capacitors C and D are in parallel.
Add the systems of capacitors together. They are in series.
The total capacitance is
The equation for finding the energy of a capacitor is:
Plug in known values and solve.
Therefore, the system, when fully charged, holds
Compare your answer with the correct one above
Suppose I have a uniform electric field within a parallel plate capacitor.
Suppose the capacitor's plates are 
in length and 
in width, and the space between the plates is 
.
Given that the capacitance is 
, at what voltage difference is required for the capacitor to store 
of charge?
Suppose I have a uniform electric field within a parallel plate capacitor.
Suppose the capacitor's plates are
Given that the capacitance is
To determine this, we can use the formula:
Where 
is charge stored, 
is voltage difference across a capacitor, and 
is capacitance.
Solving for 
,
To determine this, we can use the formula:
Where
Solving for
Compare your answer with the correct one above