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Step 4General rules
These are the general rules for series and for parallel circuits.
Instead of WIRES carying ELECRICITY, imagine that you have PIPES carrying WATER. Water PRESSURE is analogus to VOLTAGE, RESISTANCE to the flow of water (rough surface for exmaple) is analogous to RESISTANCE to the flow of electricity, The AMOUNT of water flowing in/out the PIPE is analogous to the CURRENT (AMPERES) that is available in an electical circuit. See the drawing below.
IN SERIES::: For a series of pipes connected in a closed loop::: Select a point in the loop as the beginning. That point is also the end point::: There is only one path through the loop::: The loop is like the figure z-e-r-o.
SERIES pipes are linked end-to-end. If a constant PRESSURE is maintained on the water in the pipe, you can draw the same AMOUNT of water in a given time no mater where you tape (or punch) the pipe. AMOUNT=CURRENT=AMPERES: ***IN A SERIES CIRCUIT THE CURRENT IS THE SAME IN ALL PARTS ***.
It makes sence that the total resistance in the series of pipes is equal to the SUM of the resistance in the individual sections of pipe. Where else could the resistance come from? ***IN A SERIES CIRCUIT Rt=R1+R2+....Rx*** Total resistance equals the sum of all the individual resistances.
Starting from a point in the SERIES loop, the PRESSURE will drop in successive sections of pipe because of resistance to flow. The sum of all the drops in pressure across all the sections of pipe in the SERIES loop is the same as the drop in pressure at the starting piont: ***IN A SERIES CIRCUIT, THE VOLTAGE DROP IS EQUAL TO THE SUM OF THE VOLTAGE DROPES ACROSS EACH COMPONENT***
IN PARALLEL::: Using the water pipe analogy, think of pipes connected together in the form of the figure e-i-g-h-t::: From any given starting point there is more than one path or branch in which water can flow. The secret for dealing with parallel circuits is to isolate each BRANCH and use the SERIES rules described above to find an EQUIVALENT RESISTANCE for each BRANCH(Req1 and Req2 in this case). This in effect reduces the circuit to TWO RESISTANCES (Req1 and Req2) in SERIES. As with SERIES circuits, TOTAL RESISTANCE is the sum of the individual resistances - Rpt=Req1+Req2 in this case.
Study the example in Photo 5 with care. Once you understand this example you will be confident when solving similar problems.
Instead of WIRES carying ELECRICITY, imagine that you have PIPES carrying WATER. Water PRESSURE is analogus to VOLTAGE, RESISTANCE to the flow of water (rough surface for exmaple) is analogous to RESISTANCE to the flow of electricity, The AMOUNT of water flowing in/out the PIPE is analogous to the CURRENT (AMPERES) that is available in an electical circuit. See the drawing below.
IN SERIES::: For a series of pipes connected in a closed loop::: Select a point in the loop as the beginning. That point is also the end point::: There is only one path through the loop::: The loop is like the figure z-e-r-o.
SERIES pipes are linked end-to-end. If a constant PRESSURE is maintained on the water in the pipe, you can draw the same AMOUNT of water in a given time no mater where you tape (or punch) the pipe. AMOUNT=CURRENT=AMPERES: ***IN A SERIES CIRCUIT THE CURRENT IS THE SAME IN ALL PARTS ***.
It makes sence that the total resistance in the series of pipes is equal to the SUM of the resistance in the individual sections of pipe. Where else could the resistance come from? ***IN A SERIES CIRCUIT Rt=R1+R2+....Rx*** Total resistance equals the sum of all the individual resistances.
Starting from a point in the SERIES loop, the PRESSURE will drop in successive sections of pipe because of resistance to flow. The sum of all the drops in pressure across all the sections of pipe in the SERIES loop is the same as the drop in pressure at the starting piont: ***IN A SERIES CIRCUIT, THE VOLTAGE DROP IS EQUAL TO THE SUM OF THE VOLTAGE DROPES ACROSS EACH COMPONENT***
IN PARALLEL::: Using the water pipe analogy, think of pipes connected together in the form of the figure e-i-g-h-t::: From any given starting point there is more than one path or branch in which water can flow. The secret for dealing with parallel circuits is to isolate each BRANCH and use the SERIES rules described above to find an EQUIVALENT RESISTANCE for each BRANCH(Req1 and Req2 in this case). This in effect reduces the circuit to TWO RESISTANCES (Req1 and Req2) in SERIES. As with SERIES circuits, TOTAL RESISTANCE is the sum of the individual resistances - Rpt=Req1+Req2 in this case.
Study the example in Photo 5 with care. Once you understand this example you will be confident when solving similar problems.
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