Question

Which of the following is a derived unit?
A. Speed
B. Time
C. Length
D. Mass

Answer 1

Hint: The derived unit is a combination of two fundamental quantities which have their SI base unit and treated as an independent quantity. The dimension of the derived unit is expressed in terms of base units.

Complete step by step answer:
The derived unit is defined as the unit which is which results from the combination of SI base units.
The SI base units are founded on seven SI base units which are used for seven base quantities and each quantity is mutually independent. It is a fundamental quantity which is an independent physical quantity which cannot be used to express other physical quantities. It is used as a pillar for derived quantities.
Speed is the measure of how fast a substance can move. Speed is a derived unit whose SI derived unit is meter per second which is abbreviated as m/s. Speed is the combination of two fundamental quantities distance and time.
The time is defined as the continued progress in past, present and future. Time is a base quantity whose SI base unit is second which is abbreviated by s.
The length is defined as the pathway covered by light in a vacuum in a duration of 1/299792458 seconds. Length is a base quantity whose SI base unit is meter which is abbreviated by m.
Mass is defined as the matter available in a substance. Mass is a base quantity whose SI base unit is kilogram which is abbreviated by Kg.
So, the correct answer is “Option A”.

Note:
The derived units are in unlimited numbers as they are derived from the different mathematical operations on the base units.