Kirchoff’s second law

The algebraic sum of the EMFs is equal to the sum of potential differences around a closed loop.

This essentially means that:

We can write this as:

\sum \epsilon = \sum V

Example

In a simple circuit, a battery of EMF 12V is connected in series with two resistors of resistance 2\Omega and 4\Omega. Calculate the potential difference across each resistor.

flashcards

QuestionAnswer
What is Kirchhoff’s second law?The algebraic sum of the EMFs is equal to the sum of potential differences around a closed loop.
What does Kirchhoff’s second law essentially mean?The total EMF supplied by the power source equals the total potential difference across the components in the loop.
What is the equation for Kirchhoff’s second law?\sum \epsilon = \sum V
In a series circuit with a 12V battery, a 2\Omega resistor, and a 4\Omega resistor, what is the total resistance?2\Omega + 4\Omega = 6\Omega
In a series circuit with a 12V battery and two resistors (2\Omega and 4\Omega), what is the total potential difference across the resistors?12V (equal to the total EMF)
Using V=IR, with a 12V battery and total resistance of 6\Omega, what is the current in the circuit?I = \frac{V}{R} = \frac{12V}{6\Omega} = 2A
What is the potential difference across the 2\Omega resistor in the example circuit?V = IR = 2A \times 2\Omega = 4V
What is the potential difference across the 4\Omega resistor in the example circuit?V = IR = 2A \times 4\Omega = 8V