PHYS 212 Lecture : lecture 8

A parallel-plate capacitor is filled with a dielectric whose dielectric constant is K, increasing its capacitance from C₁ to KC₁. A second capacitor with capacitance C₂ is then connected in series with the first, reducing the net capacitance back to C₁. What is the capacitance C₂ of the second capacitor?

The plates of a parallel-plate capacitor have constant charges of+Q and -Q. Do the following quantities increase, decrease, orremain the same as a dielectric is inserted between theplates?

the electric field between the plates

the potential difference between the plates

the capacitance

the energy stored in the capacitor

A capacitor has a capacitance of 70 pF, which increases to 190pF when a dielectric material is between its plates. What is thedielectric constant of the material?