✔ Wheatstone Bridge Variable Resistor

Defined simply a wheatstone bridge is an electric circuit that is used to measure the electrical resistance of a circuit. In our tutorial about resistors in series we saw that each resistor within the series chain produces an ir drop or voltage drop across itself as a consequence of the current flowing through it as defined by ohms law.

Module 2

Wheatstone Bridge Part 1 Principles And Basic Applications

Ohm S Law Verification And Wheatstone Bridge

When balanced the wheatstone bridge can be analysed simply as two series strings in parallel.

Wheatstone bridge variable resistor. A wheatstone bridge is an electrical circuit used to measure an unknown electrical resistance by balancing two legs of a bridge circuit one leg of which includes the unknown componentthe primary benefit of the circuit is its ability to provide extremely accurate measurements in contrast with something like a simple voltage divider. The concept of wheatstone bridge. By using a wheatstone bridge the unknown electrical resistance value can easily measure.

The wheatstone bridge circuit an example of a circuit that cannot be reduced using simple series and parallel rules appears the wheatstone bridge circuit above is usually operated by adjusting the variable resistor r3until no current flows in the ammeter. When the variable resistor is adjusted then the current in the galvanometer becomes zero the ratio of two two unknown resistors is equal to the ratio of value of unknown resistance and adjusted value of variable resistance. In the above circuit two resistors r 1 and r 2 are equal to each other and r 3 is the variable resistor.

The bridge is used for finding the value of an unknown resistance connected with two known resistor one variable resistor and a galvanometer. The below figure shows the wheatstone bridge where the unknown resistor is replaced with a strain gauge. To find the value of unknown resistance the deflection on galvanometer made to zero by adjusting the variable resistor.

The circuit is set out by balancing two legs of a bridge circuit. An electrical circuit that is set up to measure the unknown value of a resistor and creates a balance between the two legs of the bridge circuit is called a wheatstone bridge. This point is known as balance point of wheatstone bridge.

As shown in the figure below three resistances are known one is variableadjustable and the fourth one has to be found out. Out of the two one of the legs is an unknown component which was invented by samuel hunter christie in the year 1833 and later it improved and popularized by sir charles. As we can.

When the current through the galvanometer becomes zero the ratio of two known resistors is exactly equal to the ratio of adjusted value of variable resistance and the value of unknown resistance. Wheatstone bridge analysis and calculator the illustration below shows a basic bridge circuit which consists of three known resistances r 1 r 2 and r 3 variable an unknown variable resistor r x rtd a source of voltage and a sensitive ammeter. Its operation is similar to the original potentiometer.

By adjusting the variable resistor the current through the galvanometer is made zero. Under this special circumstance the above circuit problem may be. Consider the series circuit below.