A bridge circuit, also known as a Wheatstone bridge, is used to measure an unknown resistance. It consists of four resistors arranged in a square: two resistors R_1 and R_2 on one branch, and R_3 and R_x (the unknown resistor) on the other. A voltage source is connected across two opposite points, and a voltmeter is placed across the other two.
Practical Example: Temperature Measurement
A bridge circuit can measure temperature using a PT100 sensor. The sensor acts as R_x and changes resistance with temperature. Changes in resistance cause a voltage difference, which can be used to determine the temperature.
The Wheatstone bridge is widely used for precise resistance measurements and sensor applications, such as strain gauges and temperature
