Parallel plate capacitor
:sm40:
Question 1:
A parallel-plate capacitor with circular shaped plates, with a diameter of 4 cm and air-gap separation of 0.50 mm is connected to a 12 V battery, and fully charged. The battery is then disconnected, what is the charge on the capacitor?
Question 2:
Consider a charged parallel-plate capacitor. How can its capacitance be halved? Check all that apply from the list below and show how:

- Double the charge.
- Double the plate area.
- Double the plate separation.
- Halve the charge.
- Halve the plate area.
- Halve the plate separation.
Question 3:
Consider a charged parallel-plate capacitor. Which combination of changes would quadruple its capacitance and show how?
- Double the charge and double the plate area.
- Double the charge and double the plate separation.
- Halve the charge and double the plate separation.
- Halve the charge and double the plate area.
- Halve the plate separation and double the plate area.
- Double the plate separation and halve the plate area.
:sm51:
Question 4:
A parallel plate capacitor is formed from two square pieces of ****l 0.040 m on a side. The plates are separated by 0.008 m, and the space between them is filled with insulating rubber, which has a dielectric constant of 6.7. When this capacitor is connected to a 25 volt battery, what is the magnitude of the charge on each plate?

ـــــــــــــــــــــــــــــــــــ ـــــــــــــــــــــــــــــــــــ ـــــــــــــــــــــــــــــــــــ
:sm52:
Parallel plate capacitor

Question 1:
If you knew that the dielectric constant of glass is 7.6 and of polystyrene is 2.5, find the percentage error in your experiment.
Question 2:
A parallel-plate capacitor has rectangular plates of area 57 cm2 (length=19 cm and width=3 cm). The region between the plates is filled with a dielectric slab of dielectric constant K= 4 which can slide along the length of the capacitor. Initially, the slab completely fills the rectangular region, and the capacitor holds a charge of 0.1 µC. How far should the dielectric slab be pulled so that the stored energy is double its initial value?