Parallel Circuit (discussion) | Series And Parallel Circuits | Resistor

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Parallel Circuit Parallel circuit is a circuit wherein each device is placed in its own separate branch. The presence of branch lines means that there are multiple pathways by which charge can traverse the external circuit. Each charge passing through the loop of the external circuit will pass through a single resistor present in a single branch. When arriving at the branching location or node, a charge makes a choice as to which branch to travel through on its journey back to the low potential terminal. Resistance in Parallel Circuit Resistors are said to be connected together in parallel when both of their terminals are respectively connected to each terminal of the other resistor or resistors. The equivalent resistance of the circuit is the summation of the reciprocal ( 1/R ) value of the individual resistances with the inverse of their algebraic sum. The total circuit resistance ( RT ) of any two resistors connected together in parallel will always be less than the value of the smallest resistor in that combination. Current in Parallel Circuit Current flowing through each resistor would definitely be different as the value of the resistors varies. But, using Ohm’s Law, the current through each resistor can be determined. And the smaller the resistance, the more current will flow through the resistor. The total current, IT in a parallel resistor circuit is the sum of the individual currents flowing in all the parallel branches. The amount of current flowing in each parallel branch is not necessarily the same as the value of the resistance in each branch determines the current within that branch. Total current can be calculated using the principle of Kirchhoff’s Current Law (KCL) which states that the total current leaving a circuit is equal to that entering the circuit. Voltage Drop of Each Resistor in Parallel Circuit The potential drop of each branch is equal to the potential rise of the source. Meaning, voltage across each resistor is the same as the voltage across the parallel combination. The total voltage drop in the external circuit is equal to the gain in voltage as a charge passes through the internal circuit. In a parallel circuit, a charge does not pass through every resistor; rather, it passes through a single resistor. Thus, the entire voltage drop across that resistor must match the battery voltage. It doesn’t matter whether the charge passes through resistor 1, resistor 2, or resistor 3, the voltage drop across the resistor that it chooses to pass through must equal the voltage of the battery. http://www.physicsclassroom.com/Class/circuits/U9L4d.cfm http://www.electronics-tutorials.ws/resistor/res_4.html http://www.regentsprep.org/regents/physics/phys03/bparcir/ http://epb.apogee.net/foe/fcsppr.asp