What is the capacitance of a 20-microfarad capacitor connected in series with a 50-microfarad capacitor?

Capacitors behave exactly opposite to resistors and inductors when it comes to series and parallel combinations. When capacitors are connected in series, the total capacitance is less than the lowest value capacitor in the string. To calculate the total capacitance of two capacitors in series, you use the product-over-sum formula or the reciprocal formula: Ct = 1 / (1/C1 + 1/C2). Plugging in the numbers: 1 / (1/20 + 1/50) = 1 / (0.05 + 0.02) = 1 / 0.07, which equals 14.28 microfarads. This rounds to 14.3 microfarads. The 70 microfarad option is a strong distractor because it represents what you would get if you mistakenly added the values together as you would for inductors or resistors in series.