resistance reactance and impedance you've likely encountered these terms before but do you truly understand their significance let's unravel the Mysteries Behind These Concepts when we apply a voltage difference across a conductor connected to a light bulb using any kind of power supply the light bulb will turn on let's represent the voltages at the two ends of the circuit using a scale like this when the voltage is equal on both sides A and B the light will not turn on because no current flows let's set the a end to 0 volts and increase the voltage at
the B end if the voltage at B exceeds that of a current will flow from B to a conversely if the voltage at B drops below that of a current will flow from A to B when the voltage difference between a and b remains constant we call it direct current when the voltage varies and current changes in magnitude and Direction frequently we refer to it as alternating current to gain a better understanding of these two types of currents we can graph voltage and current in DC circuits voltage remains constant resulting in a constant current to
simplify we'll overlay both charts in AC circuits voltage varies in a sine wave pattern causing the current to follow the same pattern again for clarity we'll overlay both charts having a solid grasp of these two types of currents is essential as we move forward this is a current conducting wire for example let's assume it conducts the alternating current when we connect electronic components to this current carrying wire they have the power to influence and modify the behavior of the current in a DC circuit each component connected to the current path impedes the movement of electrons
resulting in a decrease in current flow this phenomenon also occurs in AC circuits a component can hinder electron flow causing a reduction in current much like in a DC circuit however it's important to note that in AC circuits current typically follows the voltage increasing and decreasing in sync with it but that's not the sole way current behavior changes in AC circuits as voltage changes some components resist the change causing the current to not strictly follow voltage fluctuations conversely others accelerate the current changes further complicating the relationship between voltage and current in AC circuits we have
now discussed three types of current changes in a circuit and these changes depend dep on whether the type of current flowing through the circuit is AC or DC the first type involves simply decreasing the magnitude of current and it can be observed in both DC and AC circuits in this scenario current and voltage changes occur simultaneously the second type entails current changes occurring after some time following a voltage change this phenomenon is unique to AC circuit since in DC circuits voltage remains constant the third type involves current changing before a voltage change and it is
also exclusive to AC systems we say the first type of current change to the resistance of a component the second and third types of changes occur due to the reactance of the components more specifically inductive reactants causes the current to lag behind the voltage while capacitive reactants causes the current to lead the voltage now let's discuss resistance and reactance to gain a better understanding of these Concepts we need to explore the behavior of resistors inductors and capacitors let's try to grasp these Concepts using a water analogy here we have two Pistons each half filled with
water and both connected using a water pipe if we apply a constant pushing force to piston a the water will begin to flow from piston a to piston B this happens because the applied force increases the water pressure in piston a prompting the water to move from the high pressure region to the low pressure region the same phenomenon occurs in an electric circuit a battery has two terminals positive and negative the positive terminal has a high potential while the negative terminal has a low potential when we connect these two terminals using a conductor wire a
current begins to flow from the positive side to the negative side let's return to the water piston example if we modify the applied force the water flow will also change accordingly we can represent the applied force and the water flow in graphs when the the pushing force decreases the water flow from A to B also decreases if we apply a pulling Force to the Piston it can be represented in the graph as a negative Force resulting in water flowing from B to a to provide a clearer perspective let's combine these two graphs like this this
water analogy serves as an analogy for AC circuits now let's examine the impact on water flow when different types of components are connected to the water path here's our setup we are applying a constant force to piston a resulting in a steady water flow in the pipe now what happens if we connect a narrow nozzle to the water pipe it's quite straightforward if the force Remains the Same as before the narrow nozzle decreases the water flow in the pipe whether the force remains stable or changes Direction the reduction in water flow is noticeable in both
scenarios the same principle applies to an electric circuit when we connect a resistor the resistor diminishes the current flow through it as we mentioned at the beginning of this video resistance opposes the flow of current and is present in both AC and DC circuits here we have a water wheel connected to the water pipe blocking the water's path to initiate water flow the wheel must begin to rotate let's illustrate this with a graph of the applied force and water flow initially there is no force on the Piston resulting in no current flow through the pipe
when we suddenly increase the force on the Piston the water flow cannot immediately increase it needs to set the wheel in motion first consequently the wheel starts to rotate gradually increasing the water flow after a while it reaches a constant speed if we abruptly stop the force while the wheel is still turning the wheel will attempt to maintain its rotation causing the water flow to persist for a moment before gradually decreasing and eventually coming to a halt due to friction within the pipe this Behavior arises from the inertia of the water wheel which strives to
maintain a constant rotational speed from this we observe some interesting characteristics the water wheel delays the increase in water flow the water wheel delays the decrease in water flow when the force remains constant the water wheel does not impact water flow behaving like an ordinary pipe when the force changes continuously the water flow only responds after a delay in general terms we can say the water wheel resists abrupt changes in water flow if the water flow is steady the water wheel does not interfere with it however if the water flow attempts to change the water
wheel delays this change this Behavior parallels that of an inductor in an electrical circuit in the case of direct current DC where voltage remains constant the inductor does not influence the current however in alternating current AC circuits where voltage is always leading the current this effect becomes evident this phenomenon is known as inductive reactants as we mentioned earlier in this video inductive reactants does not like to change the current through it also it is not observed in DC circuits because current remains constant here we have an elastic chamber connected to the waterpipe serving as a
barrier between both sides water inside a cannot move to side B and vice versa we'll color the water inside B using green dye the colored water cannot mix with the water inside a due to the membrane's impermeability however since it's an elastic membrane it can expand to a certain extent based on the water pressure difference between the two sides when we apply a pushing force to piston a the membrane expands as shown however the water flow stops when the opposing elastic Force equals the applied force we can graph the applied force and water flow like
this when the applied force is constant no water flows through the pipe but when the force changes we observe water flowing through the pipe like this it appears that the water flow must change before the force changes in general terms we can say that the elastic membrane tends to influence water flow changes to delay Force changes in this example the water flow is leading the voltage if the force remains constant no water flows through the pipe however if the force changes the water flow leads the force this Behavior closely mirrors how a capacitor operates in
an electrical circuit in direct current where the voltage is constant the capacitor does not allow current to pass through but in all alternating current current consistently leads voltage this phenomenon is referred to as capacitive reactants as we mentioned at the beginning of this video capacitive reactance is not observed when the voltage remains stable since current does not change in DC circuits capacitive reactant is not evident in DC circuits now that we understand how different types of components affect the current in a circuit the three primary factors influence current are resistance inductive reactants and capacitive reactants
resistance consistently decreases the current and is observable in both AC and DC circuits inductive reactants causes the current in a circuit to lag behind the voltage and it's exclusively observable in AC circuits conversely capacitive reactants makes the current lead the voltage and it two can only be observed in AC circuits the cumulative effect of these factors is referred to to as impedance in simple terms impedance of a component signifies how it modifies the current within a circuit that's all for today if you think my contents are valuable to the world you are welcome to join
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