Question

Relative permittivity of water is $81$. If ${ϵ}_w$ and ${ϵ}_0$ are permittivities of water and vacuum respectively, then :

• A. ${ϵ}_0=9{ϵ}_w$
• B. ${ϵ}_0=81{ϵ}_w$
• C. ${ϵ}_w=9{ϵ}_0$
• D. ${ϵ}_w=81{ϵ}_0$

Answer 1

The correct option is D ${ϵ}_w=81{ϵ}_0$

The relative permittivity is defined by:

${ϵ}_{rel}=\frac{{ϵ}_w}{{ϵ}_0}=81$

Hence, ${ϵ}_w=81\times {ϵ}_0$