DC Circuits

These were out predictions for what would happen in each setup as the switched were flipped. We ended being wrong in every prediction except for what we assumed would happen in the lower bulb in the second setup. In the top setup, it is essential the same circuit no matter which way the switch is flipped. In the lower circuit, when the switch is flipped as to include the third batter, an extra flow of charge is introduced into the top light bulb, while the same current runs through the bottom light bulb.

We observe that bulbs connected in series are glow dimmer than those that are in parallel. We also see that batteries connected in series allow a bulb to glow brighter than when the batteries are in parallel.

Here is an activity from the lab book that we had to do. 

We were given a set of resistors in order to learn the meaning behind each colored band on the resistor. If the last band is gold or silver band, there is an uncertainty of 5% or 10 % respectively. 

When connected in series, the equivalent resistance of the circuit is the algebraic sum of each resistor. In parallel, the equivalent resistance is as shown on the bottom of the board.

In this activity, we were told to find the equivalent resistance in the circuit. When there are both parallel and series attributes in a circuit, it helps to reduce the parallel portion in such a way that you can of the equivalent resistance of that portion in series with the rest of the circuit.

Passing through a source from the side of lower potential to the side of higher potential increases the potential. If you were to continue in this direction, adding or subtracting all the changes in voltages along the way, by the time you return to the source, the voltage should be zero. Passing through a resistor in the direction of current reduces potential, and passing through a resistor against the current increases the potential. Since you don't originally know the direction of the current, you must initially assume. If you end up calculating a current with a negative sign, the direction of the current is opposite to that of your assumption.