2.2 Series and parallel circuits

Question 1

Series circuits

Answer 1

The current is the same at all points ie. through each component.
The total potential difference of the power supply is shared between the components.
The total resistance of two components is the sum of the resistance of each component.

Question 2

Parallel circuit

Answer 2

The total current through the whole circuit is the sum of the currents through the separate components.
The potential difference across each component is the same.
The total resistance of two resistors is less than the resistance of the smallest individual resistor.

Question 3

Resistance in series circuits

Answer 3

When two or more resistors are connected in series, the total resistance is equal to the sum of their individual resistances.
For two resistors of resistance R1 and R2, the total resistance can be calculated using: R = R1 + R2 + R3…
Where R is the total resistance, in Ohms (Ω).
Increasing the number of resistors increases the overall resistance, as the charge now has more resistors to pass through.

Question 4

Resistance in a parallel circuit

Answer 4

When two or more resistors are connected in parallel, the combined resistance decreases.
This happens because each resistor creates an extra path along which the charge can flow.
This allows more charge to flow overall.
This leads to a smaller overall resistance.
The advantages of this kind of circuit are:
The components can be individually controlled, using their own switches.
If one component stops working the others will continue to function.