Question

The reference standard used for the measurement of a physical quantity is called:
(A) Standard quality
(B) Dimension
(C) Constant
(D) Unit

Answer 1

Hint: Looking into the definition of each unit clearly says that it is an internationally accepted way to measure the physical quantities and hence called a reference standard.

Complete step – by - step solution:
The definition of the unit says that measurement of any physical quantity involves comparison with a certain basic, arbitrarily chosen, internationally accepted reference standard.
Using this measurement we come to know that quantity of any kind of the physical quantity. It is in terms of units that physical quantities like mass, speed, time and more are calculated.
Units are also classified in terms of systems like S.I, FPS, CGS, and MKS.
Units have seven fundamental or base or absolute units from which the units of other physical quantities are derived and hence are called derived units.

So, the correct option is D.

Note: Apart from fundamental and derived units we use supplementary units, plane angle and solid angle and practical units for example light year is a practical unit of distance and horsepower is a practical unit of power.