Question

How does a bridge circuit work?

Answer 1

1. The bridge circuit was created in the past to determine the values of unknown resistances, but it is now possible to accomplish so using some cutting-edge contemporary methodologies.
2. As indicated in the diagram, a bridge circuit is built by combining four resistances in series and parallel to form a diamond-shaped circuit.
3. Two known resistors, one unknown resistor, and one variable resistor whose value can be altered based on our needs are required to determine an unknown resistance using a Wheatstone bridge.
4. The ratio of two known resistors to the ratio of the variable and unknown resistor will be identical when the current in the galvanometer drops to zero and the bridge is balanced, and the value of the unknown resistor may then be determined with ease.

When the current flowing through the galvanometer in the above circuit is zero, the following situation occurs.$\frac{I_1}{I_2}=\frac{R}{P}$

If a galvanometer is absent, this circuit can be used as a voltage divider just like other circuits if one is present. From high resistance (mega ohms) to low resistance can be measured using a bridge circuit (Milliohms or micro ohms).

Note: Bridge circuits can be useful for accurately measuring unknown resistance measuring strain, temperature, etc., or for measuring capacitance or inductance with a variety of fluctuations. The majority of thermometer readings employ the fractional measurement of resistance in a bridge circuit.