Resistors in Series & Parallel Flashcards

All 7 cards in this deck

What is the total resistance of two resistors connected in series?

e.g. a $3\ \Omega$ and a $5\ \Omega$ resistor in series

The sum of the two resistances: $R_{total} = R_1 + R_2 = 3 + 5 = 8\ \Omega$.

How does the total resistance of two resistors in parallel compare with their individual resistances?

The total resistance is less than the resistance of the smallest individual resistor.

What effect does adding another resistor in series have on the total resistance of a circuit, and why?

It increases the total resistance — the charge still has only one path, and it must pass through both resistances, so the resistances add.

What effect does adding another resistor in parallel have on the total resistance of a circuit, and why?

It decreases the total resistance — there are more paths for the charge to flow, so the total current is greater for the same potential difference.

True or false? The total resistance of two resistors in parallel is found by adding their resistances.

False. Adding resistances only works in series; in parallel the total resistance is less than the smaller resistor.

What are the steps to find the current in a series circuit using equivalent resistance?

e.g. a $6\ V$ battery with a $2\ \Omega$ and a $4\ \Omega$ resistor in series

1. Add the resistances: $2 + 4 = 6\ \Omega$
2. Use $I = \frac{V}{R}$: $I = \frac{6}{6} = 1\ A$

What are the steps to find the potential difference across one resistor in a series circuit?

e.g. a $2\ \Omega$ and a $4\ \Omega$ resistor in series with a current of $1\ A$

1. The current is the same through every component: $1\ A$
2. Use $V = IR$ for that resistor: $V = 1 \times 2 = 2\ V$ across the $2\ \Omega$ resistor