Series and Parallel Circuits

In a series circuit, all components are connected end-to-end in a single loop.
This means that the current flowing through each component is the same. If one component fails, the whole circuit will stop working.
The total resistance R_total in a series circuit is the sum of the resistances of each component.
The total voltage V_total supplied by the power source is distributed or ‘dropped’ across the components according to their resistances.

In a parallel circuit, components are connected side by side, forming separate paths for the current to move along.
This means that if one component fails, the rest of the circuit can still function.
The total current I_total in the circuit is the sum of the currents through each branch.
Each branch in a parallel circuit has the same voltage. The voltage across each component in the branches is the same as the supply voltage.
The total resistance in a parallel circuit can be calculated using the formula 1/R_total = 1/R1 + 1/R2 + ... + 1/Rn, where R1, R2,..., Rn are the resistances of the components.

In series circuits, current is the same but voltage varies. In parallel circuits, voltage is the same but current varies.
If components are in series, the whole circuit fails if one component fails. In parallel circuits, the rest of the circuit can continue to function even if one component fails.
Calculating total resistance differs between series and parallel circuits.

Series circuits are commonly used in battery-operated devices and Christmas lights. When one component or light goes out, the circuit breaks and all the other lights go out too.
Parallel circuits are used in houses and cars due to their reliability. If one light goes out, it doesn’t affect any other light or circuits.
Both series and parallel circuits have practical applications and their choice depends on the needs for reliability, control, and power efficiency.