Electronics - Direct Electric Current (Module 13)

Question 1

What is the first current rule? (Otherwise known as Kirchhoff’s first law)

Answer 1

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

Question 2

What is the second current rule?

Answer 2

If components are in series:

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

Question 3

What is the first potential difference rule?

Answer 3

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 4

What is the second potential difference rule?

Answer 4

The pd across components in parallel is the same

Question 5

What is the third potential difference rule? (Otherwise known as Kirchhoff’s second law)

Answer 5

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

Question 6

For resistors in series, how do you calculate the total resistance?

Answer 6

It is equal to the sum of the individual resistances

R= R1 + R2 + R3 +…..

Question 7

For resistors in parallel, how do you calculate the total resistance?

Answer 7

R = 1/R + 1/R2 + 1/R3 + …..

Question 8

How do you calculate the rate of heat transfer?

Answer 8

I^2 x R (Current squared times resistance)