Exam Question

### (a) Method to Measure the Capacitance of a Capacitor (6 Marks)
A highly accurate and common method for measuring the capacitance of an unknown capacitor is by using an AC bridge circuit, specifically the **De Sauty Bridge**. This method operates on the same null-indication principle as the Wheatstone bridge used for measuring resistance.
**1. Principle:**
The De Sauty Bridge compares the unknown capacitor with a known standard capacitor. The bridge is balanced when the ratio of resistances in one pair of arms is equal to the ratio of capacitances in the other pair of arms. At the balance point (null point), no current flows through the detector.