How many milliamperes is 1.5 amperes?

The metric prefix 'milli-' means one-thousandth (1/1000) of a base unit. Therefore, one full ampere is equal to 1,000 milliamperes. To convert from a larger unit (amperes) to a smaller unit (milliamperes), you multiply the value by the conversion factor of 1,000. Multiplying 1.5 amperes by 1,000 yields 1,500 milliamperes. Other options represent common decimal placement errors, such as dividing by 1,000 to get 0.0015 mA or multiplying by 1,000,000 to get 1,500,000 mA. Always remember that 'milli' requires moving the decimal point exactly three places to the right when converting from the base unit.