Can a physical quantity have two or more units? Does the outcome of measurement depend on the system of unit used to make measurement? Is there any relation between the measures of a physical quantity using different units? If yes write the relation. 

Yes. A Physical quantity cannot have more than two units. The outcome of the measurement does not depend on the system of unit used to make the measurement. That is, the magnitude of a physical quantity remains same whatever the system of unit is used.

 Let two units u₁ and u₂ be used to measure a physical quantity X. If n₁ and n₂ are the numerical factors of measure, then

                         X = n₁u₁ = n₂u₂