What is the optical dielectric constant 'ε' ?

Question

please i think it's 9 x 10^9 but cant find any internet source to back it up. not in my textbooks either :(

Answer 1

The dielectric constant is the relative permittivity of a dielectric material. For vacuum (εr) =1

Glass 5-10

Mica 3-6

Mylar 3.1

Neoprene 6.70

Plexiglas 3.40

Polyethylene 2.25

Polyvinyl chloride 3.18

Teflon 2.1

Germanium 16

Strontiun titanate 310

Water 80.4

Glycerin 42.5

Liquid ammonia(-78°C) 25

Benzene 2.284

Air(1 atm) 1.00059

Air(100 atm) 1.0548

(ε0) = vacuum permittivity = 8.85 X 10^-12 farads/meter

The permittivity of a substance is ε = (εr)(ε0)

In practice is often used in the form

k=1/[4(pi)(ε0)] = 9 x 10^9 Nm^2/C^2 = Coulomb's Constant

In the presence of polarizable media, the effective constant will have different values. In the case of a polarizable medium, called a dielectric, the comparison is stated as a relative permittivity or a dielectric constant.

Answer 2

the optical dielectric constant will depend on the material i believe....

9x10^9 is ke or the coulomb force constant or electrostatic force constant.....