How many amps are in 1 milliamp?

• A. 0.01 A
• B. 0.1 A
• C. 0.0001 A
• D. 0.001 A

Answer: (D)

Understanding how milli- prefixes work is the key. The milli- prefix means one thousandth of a unit. So one milliamp is one thousandth of an amp. Since one amp equals 1000 milliamps, dividing by 1000 gives 1 mA = 0.001 A. This also gives a quick consistency check: 0.01 A is 10 mA, 0.1 A is 100 mA, and 0.0001 A is 0.1 mA. So the amount in amps for 1 milliamp is 0.001 A.