Question

Which of the following is not a characteristic of the standard unit?
A. It should be of convenient size
B. It should change with respect to space and time
C. It should not be perishable
D. It should be easily reproducible

Answer 1

Hint: The question talks about the basic and international system of unit and measurements, how we can know and familiar ourselves with many objects' height, depth, width, length, area and even volume.

Complete step by step answer:
Standard unit refers to a particular set of units of measurement called standard system. These are used to measure weight, length etc.
Standard unit must be convenient in size, it has to be simple when considering it in measurement and any form of complexity will not be involved.
Standard unit should not change with respect to space and time.
Standard unit must not be perishable or extinct, in that it can be found at any time and place without carrying out a special function or activity.
Standard units must be regenerated or reproducible. Standard unit can easily split and can result in other forms for the sake of continuity. More often than none must be able to give rise to other units (derived units). Where other practical units can be gotten with or without the blending of one or more standard units these derived units can be gotten even in large and small extent.
Therefore the answer is Option B, the standard unit should not change with respect to space and time.

Note:The origin and source of other units is the basic or fundamental unit where all other units can easily be found by either addition or multiplication or division or even subtraction of two or more standard or fundamental units.