Voltage Divider

 
Figure 1.3:   Divider circuits: a) voltage divider and b) current divider.

Consider the voltage divider shown in figure 1.3a. The voltage across the input source is and the voltage across the output between terminals A and B is . The output voltage from the voltage divider in thus

Example: Determine an expression for the voltage on the voltage divider in figure 1.4.

 
Figure 1.4:  Example voltage divider.

We take the bottom line in figure 1.4 to be at ground and define the current flowing between and ground to be I. Ohm's law gives

Applying Kirchoff's voltage law for the input source gives

Combining the above two results and solving for leads to