## Main Difference – Series vs. Parallel Circuits

Components in a circuit can be connected in series or in parallel. The **main difference** between series and parallel circuits is that, **in series circuits, all components are connected in series so that they all share the same curren**t whereas,

**in parallel circuits, components are connected in**.

*parallel*so that they all have the same potential difference between them## What are Series Circuits

In series circuits, there are no junctions between components. Then, according to the law of conservation of charge (Kirchoff’s first law), they have the same current flowing through them. If the circuit breaks at any point, current stops flowing through the circuit altogether.The following diagram shows a circuit, where three resistors are connected in series with the cell.

## Resistors in Series

When resistors with resistances are connected in series, as shown above, the combined resistance is given by:

In series circuits, the power dissipated across a resistor is proportional to its resistance. Ammeters, which measure current, should have very little effect on the current. Therefore, they are made to have very small resistances and should e connected in series with the component.

## Inductors in Series

When inductors with inductances are connected in series, the combined inductance is given by:

## Capacitors in Series

When capacitors with capacitances are connected in series, the combined capacitance is given by:

## What are Parallel Circuits

In parallel circuits, a loop can be traced between two components without encountering other components along the loop. Then, according to the law of conservation of energy (Kirchoff’s second law) they have the same potential difference across them. If one branch of the circuit breaks, the other branches can still function. In the following diagram, the resistors are connected in parallel:

## Resistors in Parallel

When resistors with resistances are connected in parallel, as shown above, the combined resistance is given by:

When resistors are connected in parallel, the power dissipated across a resistor is inversely proportional to its resistance. Voltmeters, which measure potential differences, are always connnected in parallel to the components.

## Inductors in Parallel

When inductors with inductances are connected in parallel, the combined inductance is given by:

## Capacitors in Parallel

When capacitors with capacitances are connected in parallel, the combined capacitance is given by:

## Difference Between Series and Parallel Circuits

### Current

In **series** **circuits**, the current flowing through the components is the same.

In **parallel** **circuits**, the current flowing through each branch depends on the impedance of components in that branch.

### Potential Difference

In **series** **circuits**, the magnitude of the potential difference across a component depends on the component’s impedance.

In **parallel** **circuits**, the magnitude of the potential difference across each component is the same.

### Resistance/Inductance

In **series** **circuits**, the resistances/inductances of individual resistors/inductors add up, so that the total resistance/inductance is always greater than the largest resistance/inductance of an individual resistor/inductor.

In **parallel** **circuits**, the total resistance/inductance of resistors/inductors is always smaller than the smallest resistance/inductance of an individual resistor/inductor.

### Capacitance

In **series** **circuits**, the total capacitance of capacitors is always smaller than the smallest capacitance of an individual capacitor.

In **parallel** **circuits**, the capacitance of individual capacitors add up, so that the total capacitance is always greater than the largest capacitance of an individual capacitor.