What does mfd stand for in capacitor specifications?

What does mfd stand for in capacitor specifications?

• A. Mega Farad
• B. Milli Farad
• C. Micro Farad
• D. Pico Farad

Answer: (C)

mfd is an old shorthand for microfarad, the unit of capacitance. The micro prefix means one millionth, so 1 μF equals 1×10^-6 farads. In older electronics labeling, capacitors were often marked with the value followed by mfd, meaning the value is in microfarads. That’s why a capacitor labeled 4 mfd has a capacitance of 4 μF. Today you’ll see the same value written as μF or uF, since micro is represented by the Greek letter mu (often approximated as 'u' in plain text). The other options refer to different scales—mega farad would be vastly large and not typical for capacitors, milli farad denotes thousandths of a farad, and pico farad is a trillionth of a farad—so they don’t match the historical usage of mfd.

mfd is an old shorthand for microfarad, the unit of capacitance. The micro prefix means one millionth, so 1 μF equals 1×10^-6 farads. In older electronics labeling, capacitors were often marked with the value followed by mfd, meaning the value is in microfarads. That’s why a capacitor labeled 4 mfd has a capacitance of 4 μF. Today you’ll see the same value written as μF or uF, since micro is represented by the Greek letter mu (often approximated as 'u' in plain text). The other options refer to different scales—mega farad would be vastly large and not typical for capacitors, milli farad denotes thousandths of a farad, and pico farad is a trillionth of a farad—so they don’t match the historical usage of mfd.