What is 1 milliamp expressed in amperes?

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

Answer: (C)

Milli means one thousandth, and the ampere is the unit of current. So one milliampere is one thousandth of an ampere, which is 0.001 A. The other values are larger or smaller multiples (for example, 0.01 A is 10 mA, 0.1 A is 100 mA, and 0.0001 A is 0.1 mA), so they don’t equal 1 mA.