- A capacitor's dielectric material is a vacuum. The capacitor's dielectric constant, or K, will be equal to
I A. 1.
B. 18.
C.3.
D. 9.

If  a capacitor's dielectric constant is vacuum its dielectric constant is k will be equal to 1.

Explanation:

Relative permittivity of  a dielectric substance is referred to as its dielectric constant. Relative permittivity/dielectric constant k is a dimensionless quantity that is the ratio of absolute permittivity and vacuum permittivity.

It is given by the expression

k=k=ε /ε0

where ε denotes absolute permittivity and  ε0 denotes permittivity of vacuuum.

Absolute permittivity  ε of vacuum= ε0

therefore k= ε0/ ε0=1

dielectric constant of vacuum is 1 .