What is the formula for total resistance in a series circuit?

In a series circuit, the total resistance is determined by simply adding the resistance values of all the individual resistors connected in the series. Each resistor contributes to the overall resistance, and this accumulation of resistance prevents current from flowing, similar to the way a narrow pipe restricts the flow of water.

The correct formula for total resistance in a series circuit is represented as R_total = R1 + R2 + R3 + ..., where R1, R2, R3, etc., are the resistance values of the individual resistors. This overall resistance increases as more resistors are added into the circuit because each resistor adds to the total opposition to current flow.

In contrast, the other options either misrepresent the formula or refer to different concepts. Some imply an incorrect mathematical relationship that does not apply to series circuits, wherein resistors do not combine inversely (like in parallel circuits), nor do they multiply together to yield total resistance. Instead, the focus should always remain on the straightforward addition of the resistances for series configurations.