If a quantity is "dimensionless", that means it has no units, and it's just a number.
No, a dimensionless quantity does not have a unit because it represents a pure number without any physical dimension. Examples of dimensionless quantities include ratios, proportions, and mathematical constants.
No, a quantity cannot have units and still be dimensionless. The dimensions of a quantity are determined by its units, so if a quantity has units, it has dimensions. Dimensionless quantities are those without any units.
Efficiency is a dimensionless quantity, i.e. it's just a number, without any unit.
energy/mass example: calories/gram
No. "Dimensionless" means there are NO units involved.
Relative permeability does not have a unit as it is a dimensionless quantity that describes how easily a fluid can flow through a porous medium (such as a rock or soil) relative to the fluid's flow in a vacuum. It is typically represented as a dimensionless ratio ranging from 0 to 1.
The unit for the dielectric constant of a medium is a dimensionless quantity as it represents the ratio of the permittivity of the medium to the permittivity of a vacuum.
the dimensionless numbers have the definition as that of dimensionless groups, and have all the properties which dimensionless groups have.
infinity
Strain is dimensionless quantity because strain is the ratio of the same quantities like change in length/original length,,change in volume/original volume. e.g tensile strain=(change in length)/(original length)=m/m (S.I unit) so its a dimensionless quantity.
Angles are not dimensionless.
Yes. Conversion factors will generally be dimensionless constants.