Direct Current Circuits

Question 1

What is the current rule about components in series?

Answer 1

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

Question 2

What is the potential difference rule concerning components in series?

Answer 2

For two or more components in series, the total pd across all the components is equal to the sum of the potential differences across each component.

Question 3

What is the potential difference rule concerning components in parallel?

Answer 3

The pd across components in parallel is the same.

Question 4

What is the potential difference rule concerning any complete loop of a circuit?

Answer 4

For any complete loop of a circuit, the sum of the emfs round the loop is equal to the sum of the potential drops round the loop.

Question 5

What is the total resistance of a set of individual resistors in series?

Answer 5

Total resistance is equal to the sum of the individual resistances, so R = R1 + R2 + R3 + …

Question 6

What is the total resistance of a set of individual resistors in parallel?

Answer 6

1/R = 1/R1 + 1/R2 + 1/R3 + …

Question 7

Define internal resistance.

Answer 7

The internal resistance of a source is the loss of potential difference per unit current in a source when current passes through the source.

Question 8

When is the maximum power delivered to the load?

Answer 8

When the load resistance is equal to the internal resistance of the source.

Question 9

What is the current rule concerning junctions in a circuit?

Answer 9

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