# The capacitance of a portion of a circuit is to be reduced from 4800 pF to 2900 pF. What capacitance can be...?

The capacitance of a portion of a circuit is to be reduced from 4800 pF to 2900 pF. What capacitance can be added to the circuit to produce this effect without removing existing circuit elements? Must any existing connections be broken in the process?

please help me understand how such circuits work!

### 3 Answers

- billrussell42Lv 71 decade agoFavorite Answer
added? you remove 1900 pF to reduce 4800 to 2900 pF if they are in parallel.

if the 4800 pF is in series with an unknown C to produce 2900 pF, then

C = 4800*2900/(4800–2900) = 7300 pF

idiotic question, sorry

.

- Anonymous1 decade ago
Capacitance in series reduces capacitance. you will hae to cut an etch in the circuit or lift one end of the capacitor.

Maybe it will be useful for you to know, two factors for capacitance is determined by plate area and spacing. Putting capacitors in series increases the distance between the plates. lowering the capacitance and putting them in parallel increases the surface area, increasing the capacity.

- davidosterberg1Lv 61 decade ago
Capacitors in series are calculated like resistors in parallel.

1/2900 = 1/4800 + 1/X

x = 7326 pF

To reduce capacitance, add a series capacitor.

To increase capacitance, add a parallel cap.

To reduce resistance, add a parallel resistor

to increase resistance, add a series resistor