Voltage drop

From Electronics Wiki

Electronic devices "drop" voltage in different scenarios. Dropping voltage refers to the amount of voltage change that can be found before and after a device.

Resistors If two resistors are in line with each other, a voltage can be found between them. Ex: With a ten volt power supply, two 1 Ohm resistors are connected together across the power supply. Ohms law states that 5 amps runs through the whole circuit. Using ohms law again you can find that each resistor drops 5 volts each.

Ohms law Total Current Voltage drop over resistor

Capacitors Capacitors have two different basic scenarios when dealing with voltage drop. An unchanging current scenario, and a changing current scenario. Capacitors in an unchanging current scenario act exactly as a resistor would, except their resistance is extremely high, and varies per capacitor. A capacitor in a voltage changing scenario will drop voltage due to this rule. f being the frequency of the voltage change, and C being the capacitors value.