Question

as more lamps are put into a series circuit, the overall current in the power source
increases.
decreases.
stays the same.

Explanation:

Step1: Recall Ohm's Law

Ohm's Law is \(I = \frac{V}{R}\), where \(I\) is current, \(V\) is voltage, and \(R\) is resistance. In a series circuit, the total resistance \(R_{total}=R_1 + R_2+\cdots+R_n\).

Step2: Analyze the effect of adding lamps

When more lamps (which have resistance) are added in series, \(R_{total}\) increases. Assuming the voltage \(V\) of the power source is constant.

Step3: Determine the current change

Since \(I=\frac{V}{R_{total}}\) and \(V\) is constant while \(R_{total}\) increases, the current \(I\) (overall current in the power source) decreases.

Answer:

decreases.