Series and parallel circuits

What happens to the total emf when cells have the same polarity?

Each ones emf is added

What happens to the total emf when cells have different polarities?

Each ones emf is subtracted

State kirchoff’s 2nd law/conservation of energy

The sum of the electromotive force is equal to the sum of the potential difference in a closed loop

What is the current, voltage/pd and resistance like in series circuits?

Current is the same It = I1 + I2…

Voltage/pd is different since pd across each component is split Vt = V1 + V2…

Resistances are added up to equal the total resistance Rt = R1 + R2…

What is the current, voltage/pd and resistance like in parallel circuits?

Current in each loop adds up to the total current so it splits It = I1 + I2…

Voltage/pd is the same Vt = V1 + V2…

Resistances in each loop is added up Rt = 1/R1 + 1/R2…