Carefully examine a bulb. Two wires extend from the filament of the bulb into the base. You probably cannot see into the base, however, you should be able to make a good guess as to where the wires are attached. Describe where the wires attach. Explain based on your observations in parts A-C. On the basis of the observations that we have made, we will make the following assumptions:
1. A flow exists in a complete circuit from one terminal of the battery, through the rest of the circuit, back to the other terminal of the battery, through the battery and back around the circuit. We will call this flow electric current.
2. For identical bulbs, bulb brightness can be used as an indicator of the amount of current through that bulb: the brighter the bulb, the greater the current.
We may think of a bulb as presenting an obstacle, or resistance, to the current in the circuit.
1. Thinking of the bulb in this way, would adding more bulbs in series cause the total obstacle to the flow, or total resistance, to increase, decrease, or stay the same as before?
2. Formulate a rule for predicting how the current through the battery would change (i. e., whether it would increase, decrease, or remain the same) if the number of bulbs connected in series were increased or decreased.