# Interesting lesson on Wheatstone bridges

• orthovector

#### orthovector

I enjoy learning new things every time I do a problem set. Take the wheatstone bridge for example.

Upon my initial observation, I concluded that the total upper electric potential(V1 + V2) minus the lower electric potential(V3 + V4) ought to give the electric potential that exists across the ammeter between the upper and lower sections of the wheatstone bridge(V5). HOWEVER, this is not NOT NOT! TRUE.

The electric potential that can exist across the ammeter, R5, is V1 - V3. or, V2 - V4. And, the battery EMF is only the sum of V1 and V2 or sum of V3 and V4. the potential across R5 DOES NOT affect the amount of EMF that is necessary from the battery.

This implies that getting rid of the Ammeter and R5 connections will ONLY alter the currents across R1 and R2 or R3 and R4 without affecting the sum of V1 and V2 or V3 and V4 AND without altering the total current that comes out of the Battery.

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is everything correct?

y don't I get any more replies? this is sad...I must be incorrect...Darn!

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## 1. What is a Wheatstone bridge and how does it work?

A Wheatstone bridge is an electrical circuit that is used to measure unknown electrical resistance by comparing it with a known resistance. It consists of four resistors connected in a diamond shape with a meter or galvanometer placed between the two parallel arms. When the bridge is balanced, there is no current flow through the galvanometer, and the unknown resistance can be calculated using the known resistances and the bridge formula.

## 2. What are the applications of Wheatstone bridges?

Wheatstone bridges are commonly used in electronic circuits and measurement instruments, such as strain gauges, thermistors, and thermocouples. They are also used in industrial processes for accurate resistance measurements and in medical equipment for measuring biological signals.

## 3. What are the advantages of using a Wheatstone bridge instead of direct measurement?

Using a Wheatstone bridge allows for more accurate and precise resistance measurements compared to direct measurement methods. It also eliminates the need for high precision instruments, as the bridge uses a null method to determine the unknown resistance. Additionally, the bridge can compensate for external factors, such as temperature changes, that can affect the measurement.

## 4. Can a Wheatstone bridge be used for other types of measurements?

Yes, in addition to measuring resistance, a Wheatstone bridge can also be used to measure other physical quantities, such as capacitance and inductance, by using appropriate components in the bridge circuit.

## 5. Are there any limitations or drawbacks to using a Wheatstone bridge?

One limitation of using a Wheatstone bridge is that it requires a known resistance to be available for comparison. This can be a challenge when working with very small or very large resistances. Additionally, external factors such as temperature and humidity can affect the accuracy of the measurement, so proper calibration and compensation may be necessary.