Question

$1\mu$ is
(A) ${10}^{-6}m$
(B) ${10}^{-9}m$
(C) ${10}^{-10}m$
(D) ${10}^{-3}m$

Answer 1

Hint: To measure the quantities we define a unit for them. Meter is a unit of length. We use scientific notations to write very small or very large numbers. Scientific notation is used when a number between $1$ to $10$ is multiplied by a power of $10$ . Here, we will discuss these scientific notations, particularly, metric prefixes. They make calculations easy and error-free.

Complete answer:
We have a whole table of standard notations shown below in the picture.

A metric prefix is a unit that precedes a basic unit of measurement to indicate a multiple of the unit. All the metric prefixes used are decadic and each prefix has a unique symbol. They are very helpful, to write very large and very small measurements.
From the table, we can see that $1\mu$ is a metric prefix ${10}^{-6}$ .
Hence, the correct option is (A) ${10}^{-6}m$ .

Note:
Very common metric prefixes are centi $\left(c\right)$ , milli $\left(m\right)$ , micro $\left(\mu \right)$ , nano $\left(n\right)$ , pico $\left(p\right)$ , Giga $\left(G\right)$ , mega $\left(M\right)$ , kilo $\left(k\right)$ , hecto $\left(h\right)$ .
A metric prefix is always followed by a SI unit.
To write the numbers in scientific notation, there are some rules.
-It is always written in base $10$ and the power of $10$ carries either positive or negative signs.
-The value of the coefficient is (either positive or negative) of $10$ is less than $10$ and equal to or greater than $1$ .
-When we move the decimal to the left the power of $10$ increases. Similarly, when we move the decimal to the right, the power of $10$ decreases.