Flashcards in 2.2 - Series and Parallel Circuits Deck (13):

1

## What does a series circuit look like?

Lots of components directly connected together in a single line [Diagram TBC]

2

## What does a parallel circuit look like

Components connected in several "branches" or "loops" [Diagram TBC]

3

## For components connected in SERIES, total current is...

... the *same* through every component

4

## For components connected in SERIES, total potential difference is...

... *shared* between all components

5

## For components connected in SERIES, total resistance is...

... the *sum* of the resistance of each component

6

## For components connected in PARALLEL, total potential difference is...

... the *same* for each component

7

## For components connected in PARALLEL, total current is...

... the *sum* of the current passing through each component

8

## For components connected in PARALLEL, total resistance is...

... *less than* the resistance of the *smallest* resistor

9

## Why does total resistance increase if a resistor is added in series?

###
- Adding a component decreases the potential difference for every component
- because P.D is shared between components in series

- Decreasing the P.D. means current for every component must also decrease (V=IR)
- If current passing through each component decreases, total current also decreases
- because current is the same between components in series

- Total resistance must increase if total current decreases (V=IR)

- because P.D is shared between components in series

- because current is the same between components in series

10

## Why does total resistance *decrease* if a resistor is added in parallel?

###
- Potential Difference is unchanged by adding a resistor
- Current through the old resistors is the same as before (V = I R, with V and R unchanged)
- New resistor must also have some current (V = IR)
- Total current is greater than before (old current + new current)
- Total Resistance must be smaller than before (V = I R, with V unchanchanged)

11

## How can you measure the current flowing through a component?

###
- Create a circuit with the component
- unbroken circuit
- has a power source

- Use an ammeter
- In series (current is the same for components in series)

- unbroken circuit
- has a power source

- In series (current is the same for components in series)

12

## How can you measure the potential difference across a component?

###
- Create a circuit with the component
- unbroken circuit
- has a power source

- Use a voltmeter
- In parallel (potential difference is the same for components in parallel)

- unbroken circuit
- has a power source

- In parallel (potential difference is the same for components in parallel)

13

## How can you measure the resistance of a component?

###
- Create a circuit with the component
- unbroken circuit
- has a power source

- Measure the current passing through the component
- Ammeter
- In series (current is the same for components in series)

- Measure the potential difference passing through the component
- Voltmeter
- In parallel (potential difference is the same for components in parallel)

- Resistance is the potential difference divided by the current (V = I R )

- unbroken circuit
- has a power source

- Ammeter
- In series (current is the same for components in series)

- Voltmeter
- In parallel (potential difference is the same for components in parallel)