My son had this assignment and it is totally confusing to me.

This is the info provided:
4.5-V lightbulb
and 3 batteries that are 1.5 V each

Knowing Ohm's law: voltage (in volts) =current (in amps) x resistance (in ohms) or V=IR. Determine in which circuit the voltage was the largest and explain how you know this?

I am drawing a blank and am assuming that the circuit with all three batteries would provide the most since they have the full power then. I am not sure about this and don't know does this mean he needs to figure out what the V=IR is?

To determine in which circuit the voltage is the largest, you need to consider how the voltage is distributed in each circuit. In this situation, you are given a 4.5-V lightbulb and three batteries that are each 1.5 V.

First, let's understand how batteries are connected in series and parallel circuits:
- In a series circuit, the batteries are connected end to end, resulting in the total voltage being the sum of the individual battery voltages. For example, in this case, if the batteries are connected in series, the total voltage would be 1.5 V + 1.5 V + 1.5 V = 4.5 V.
- In a parallel circuit, the batteries are connected side by side, resulting in the total voltage being the same as the individual battery voltage. So, in this case, if the batteries are connected in parallel, the total voltage would be 1.5 V.

Now, let's analyze each circuit:

1. If the three batteries are connected in series:
- The total voltage of the three batteries would be 4.5 V.
- The current flowing through the circuit is unknown. It depends on the resistance of the lightbulb, which is not given in the information provided.

2. If the three batteries are connected in parallel:
- The total voltage of the three batteries would be 1.5 V.
- The current flowing through the circuit is unknown, as it depends on the resistance of the lightbulb.

To determine in which circuit the voltage is the largest, we need to consider the total voltage provided by each circuit. Based on the information given, it seems that the voltage would be largest in the circuit where the batteries are connected in series, resulting in a total voltage of 4.5 V.

However, to accurately determine the voltage in each circuit, we need to know the resistance of the lightbulb. Without that information, we cannot calculate or compare the currents in each circuit using Ohm's law (V=IR). So, if your son's assignment lacks the resistance value, it might be challenging to provide a definitive answer.

I recommend discussing this confusion with your son's teacher to clarify any missing information or additional requirements for the assignment.