Apr 21 2015

In this circuit, after we close the switch, the upper light ball becomes brighter while the lower become dimer.

This is our prediction before we perform this lab. Our prediction is wrong, and the reason is we didn't analysis the current and potential change correctly.

This is the list we have for the influence to bubble and battery voltage from connecting in parrallel or connecting in series.

By the color shown on the resistor, we can estimate the resistance. each color at each position stands for a factor the multiple by. We are given four this type of resistor, and this is our estimate for the resistance.

By measuring actual resistance, we found that our calculation is generally matches the actual value. Later, we calculated the total resistance by connecting them in parralles and in series.

We derived a general rule that, when connecting in series, the total resistance is just add each resistance up. when connect in parrallel, inverse of total resistance is the sum of each inverse value of each resistance.

This is a new type of question. When we doing this question, we need to obey the rule that at each loop, the total voltage is 0.

Suumarize: If we want to decrease the total resistance, we can connect resistor in parrallel while connect them in series can increase the total resistance. When we doing the question above, we need to set up the loop for direction of the current correctly, and the net voltage at each loop is 0.