Question

the absence of any medium is called​

Answer 1

Answer:

in case of electricity it is known as permittivity of free space and in case of magnetism it is known as permeability of free space

Answer 2

Answer:

Absence of medium may be defined as such condition where there is no substance in between two bodies or no presence of medium in between the two bodies.

So , absence of medium in physics can be defined in many ways but the most important ones are Electricity, Heat and magnetism.

In case of Electricity it is known as permittivity of free space.

In case of magnetism it is known as permeability of free space.

In case of heat it is known as radiation.