# Voltage Dividers

## Voltage Dividers - National 5 Recap

### In a previous section, components in Series were discussed. For a Series circuit, the Voltage across each component added up to the supply Voltage. The diagram below shows a simple series circuit containing two Resistors:- ### If the two Resistors had different Resistances, then they would share the Voltage following a ratio of their sizes:- ## Example 1 - ## Applications of Voltage Dividers

### In the above circuit, two Voltmeters were attached across the Resistors, showing the Voltage across each. If instead of a Voltmeter, an additional circuit is attached across the Resistor, this Voltage share can be used. The circuit below shows an application of this:- ## Wheatstone Bridges

### The diagram below shows a Wheatstone Bridge circuit, which consists of two Voltage dividers working against each other:- ## Example 2 -

### The diagram below shows a Wheatstone Bridge circuit. Calculate the reading on the Voltmeter. ## Balanced Wheatstone Bridges

### In the below diagram, one of the fixed Resistors (R2) has been replaced with a variable Resistor:- ### For a balanced Wheatstone Bridge, the following formula applies:- ### If a balanced Wheatstone Bridge has the Resistance of one of the Resistors changed, then the Voltmeter will show a reading. If this is plotted (up to 10% of the Total Resistor value) the following linear relationship can be found:- ## Applications of a Balanced Wheatstone Bridge

### The following diagram shows a Wheatstone Bridge sensing circuit:- 