Exam Question

(a) An accurate method to compare the capacitances of two capacitors involves using a Wheatstone Bridge configured for capacitance measurement, commonly known as a De Sauty Bridge .
The De Sauty Bridge is an AC bridge circuit specifically designed to compare two capacitors. It consists of four arms: two containing the capacitors under comparison and two containing known resistors. The bridge is balanced by adjusting these resistors until no current flows through the detector, indicating that the ratio of the capacitances is equal to the ratio of the resistances.
At balance, the ratio of the capacitances is inversely proportional to the ratio of the resistances:
$$\frac{C_2}{C_3}=\frac{R_2}{R_1}$$