Tue May 01, 2012 By:

Why does electricity pass when resistance opposes the flow of electrons?is electricity regulated by flow of electrons?

Expert Reply
Tue May 01, 2012


Electrical resistance describes how an electrical conductor (a wire) opposes the flow of an electrical current (flow of electrons). To overcome this opposition a voltage (a energy) must dropped (used) across the conductor (wire). Resistance can be described by ohms law:

Ohms Law: R = V / I (Resistance = Voltage / Current) (resistance measured in ohms)


Voltage [V]= the energy lost across an component (voltage measured in volts).

Current [I] = the charge (electrons) flowing through an component (current measured in Amps).

Electrical resistance can be thought of as sticking your hand out a car window. The faster [current] you drive the harder the wind presses [resistance] against you hand and therefore it takes more energy [voltage] to hold your steady.

When trying to overcome electrical resistance, the electrical energy lost is turned into heat. This is how the elements of a household stove, toaster, and fan heater work. Because of the vacuum in a light bulb, the electrical energy lost is instead turned into light. It can be seen the electrical resistance plays a large role in modern life.


The resistor is the most common electronic component and is used to limit and/or control the voltage and current in an electronic circuit. Resistors are carefully manufactured to provide a predetermined value of electrical resistance which may range from 0.1 ohms to 100,000,000 ohms, depending on the application. The physical size of a resistor also varies dependant on the amount of power passing through the resistor, given by:

P = V x I (Power = Voltage x Current) (power measured in watts)

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