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 .
