Circuit rules

Question 1

What is the rule for current at a junction in the circuit?

Answer 1

at any junction, the total current leaving the junction is equal to the total current entering the junction

Question 2

What are the rules for current in series?

Answer 2

the current entering a component is the same as the current leaving the component

the current passing through two or more component in series is the same through each component

Question 3

What are the rules for pd in terms of energy changes in charge carrier?

Answer 3

if the charge carries lose energy, there is a potential difference drop

vice versa

Question 4

What are the rules for pd in series?

Answer 4

for two or more components, the total pd across all of the components is equal to the sum of the potential differences across each component

pd across the battery terminals is equal to the sum of potential difference across the components

Question 5

What are the rules for pd in parallel?

Answer 5

pd across components in parallel is the same

the same amount of energy is delivered by a charge carrier regardless of which component is passes through in parallel

Question 6

What is the rule for the sum of emfs round the loop?

Answer 6

the sum of emfs round the loop, in a complete loop, is equal to the sum of the potential drops around the loop

emf in a loop is the total electrical energy per coulomb produced in the loop and the sum of the potential drops is the electrical energy per coulomb delivered round the loop

therefore energy must be conserved