Dielectric Constant: Solving Homework Problems

[jamesjd]

Homework Statement

A slab of dielectric is now inserted between the plates, the battery still being connected. 7.5μC of additional charge flows from one plate, through the battery and onto the other plate. What is the dielectric constant of the dielectric material?

Homework Equations

A 1.0μF air-spaced capacitor is connected across the terminals of a 5V battery. What charge will be deposited on the plates? How much energy is stored by the charged capacitor?

Which i calculated the charge to be 5E-6C

The Attempt at a Solution

K = C2/C1

= 7.5E-6 / 5E-6

= 1.5

Is this correct and are there any units?

 

[Astronuc]

The dielectric constant is unitless. It is basically ratio, or factor, which describes the effect of the dielectric on capacitance.

See -

http://hyperphysics.phy-astr.gsu.edu/Hbase/electric/dielec.html#c2

http://hyperphysics.phy-astr.gsu.edu/Hbase/electric/pplate.html#c1

 

[jamesjd]

thank you, are my calculations correct or am i missing something?