13.1 Circuit rules

Question 1

At any junction in a circuit, the total current leaving the junction is equal to…

Answer 1

…the total current entering the junction

Question 2

For a component in series:

The current entering a component is…

Answer 2

…the same as the current leaving the component

Question 3

For a component in series:

The current passing through two or more components in series is…

Answer 3

…the same through each component

This is because the rate of flow of charge through each component is the same at any instant

Question 4

What is the potential difference between any two points in a circuit defined as

Answer 4

The energy transfer per coulomb of charge that flows from one point to the other

Question 5

If the charge carriers lose energy, the potential difference is a potential ______.

Answer 5

Drop

Question 6

If the charge carriers gain energy, which happens when they pass through a battery or cell, the potential difference is a potential ______ equal to the pd across the battery or cell’s terminals.

Answer 6

Rise

Question 7

For two or more components in series, the total pd across all the components is equal to…

Answer 7

…the sum of the potential differences across each component

Question 8

The pd across components in parallel is…

Answer 8

…the same

Question 9

For any complete loop of a circuit, the sum of the emfs round the loop is equal to…

Answer 9

…the sum of the potential drops around the loop

Question 10

What is the total emf in a loop

Answer 10

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

Question 11

What happens each time a charge carrier goes round the circuit

Answer 11

A certain amount of energy E is transferred to it from the battery
It transfers energy equal to E/3 to the variable resistor, and 2E/3 to the light bulb