Led Schematic Diagram

Resistance, Voltage and Current?

I understand what each is. I know R=V/I and such, as well as the additive/constant properties of each in serial and parallel circuits. However, I had a quiz this morning that I failed and everyone else thought was easy.

It was a Schematic Diagram, with one parallel juncture and one series segment. The only appliances were resistors on each branch of the juncture and in the series. The resistance of each was given. The voltage of the cell was given.

I had to find the voltage and current at every resistor in the current. I don’t know how to do this. Help!

If it helps, the cell was in front of the parallel juncture (nothing in between), the juncture had three braches with 1 resistor each ( except for one which had an extra), then they came together for a 2 resistor series and led back to the cell.

N

Resistors in series form a voltage divider. The voltage from a source is divided between the resistors proportionally to their resistance, e.g. if 3V supply and a 1 Ohm and 2 Ohm resistance in series the 1 Ohm has 1 volt and 2 Ohm 2 volt. Voltages in parallel are the same. At a junction, however, the current splits so that the current coming in is equal to the sum of the two paths coming out (c.f. Kirchof’s laws). In series the current is the same.

To remember think of repeats on TV where the CURRENT SERIES is the SAME as the last one and if you change current to voltage or series to parallel you get the opposite answer. Logically think that charge can not disappear so current going out of a junction must equal current coming in and by conservation of energy the voltage of resistance in series must equal the supply.

Hope the advice helps.

My Very First SMD 8 Led Chaser