Question

1mA = __A

Answer 1

Hint : The milliampere is a unit used to measure electric current. To solve this question, we need to draw the analogue of comparison of the size of a millimeter to that of a meter.

Complete step by step answer
The Amp, or Ampere is the SI unit of current. The International Organization for Standardization symbol for Ampere is $A$ .
The sign $\text{mA}$ refers to milliampere or milliamp. This is a smaller unit of the SI unit of current, Ampere.
This prefix forms a very handy way of describing decimal fractions of a unit as well as decimal multiples. I expect you know for example the length of $\text{1 meter}$ is $\text{39}\text{.37 inches}$ . A kilometer is a thousand meters. In the other direction, there is the centimeter ( $1/\phantom{1100}100$ ) millimeter ( $1/\phantom{11000}1000$ ), micrometer ( $1/\phantom{11000000}1000000$ ) and so on.
These prefixes are used for a number of units. So now, the relative size of a milliamp can easily be compared with an amp.
The value of $\text{1mA}$ is thus smaller than the value of $1A$ and it is used to calculate smaller values.
 $\text{1mA = }\text{1}/\phantom{\text{1}\text{1000}}\text{1000}\text{A}$ .

Note
Sometimes we are dealing with very small currents, like $\text{0}\text{.002 A}$ . It is much more convenient to use a smaller unit. There are $\text{1000 mA}$ in one A. So we can write the same current from our example as $\text{2 mA}$ .
The "milli" in front of the "amps" is a prefix indicating the value is a thousandth. One milliamp is one-thousandth of an amp. One millivolt would be one-thousandth of a volt, and one milliohm would be one-thousandth of an ohm in resistance, and so on. Going the other way, one has kilo, mega, and giga, (kiloamp, Mega-amp, & Giga-amp, respectively) meaning thousand, million, and billion, respectively.