POTENTIAL DIVIDERS

==Potential Dividers== If we take two resistors in series each sharing a total PD gained by the EMF, connecting terminals on either side of one resistor will create equal potentials on the terminals. These terminals could be a source of EMF for another circuit. [image:http://i.imgur.com/x38BUi5.gif] This gives us the ability to be able to divide up potentials however we want just by using resistors in series. This is the only way to split up voltages using DC electricity. E.g. if we have a 1Ω, 2Ω and 3Ω in series with a 12V EMF, we calculate that each resistor gets 2V, 4V and 6V respectively and I have therefore divided up the potential. Using: $$V_{IN}=I(R_1+ R_2)$$ $$V_{OUT}=IR_2$$ We get $$V_{OUT}= V_{IN} \frac {R_2}{R_1+R_2}$$ Where R~2~ is the output resistor. If you wanted the output accross R~1~, replace the numerator by R~1~. Thermistors and LDRs are interesting components for use in potential dividers. V~OUT~ can be influenced by changes in the environment and specific voltages can be used to switch on and off a secondary circuit.