If a 20 mfd capacitor and a 40 mfd capacitor are installed in parallel, what is the total capacitance?

When capacitors are connected in parallel, the total capacitance is the sum of the capacitances of the individual capacitors. This principle arises because each capacitor can store charge independently, thus contributing to the overall ability of the circuit to store electric charge.

In this case, you have a 20 microfarad (mfd) capacitor and a 40 microfarad capacitor connected in parallel. The total capacitance can be calculated by simply adding these two values together:

Total Capacitance = Capacitance of first capacitor + Capacitance of second capacitor

Total Capacitance = 20 mfd + 40 mfd = 60 mfd

Therefore, the total capacitance of the circuit is 60 microfarads, which is why this is the correct answer. Understanding this method of calculating capacitance in parallel connections is crucial for practical applications in electrical engineering and circuit design.