4.1.3 Kirchhoff's First Law

• Kirchhoff's First Law states that the total current flowing into a junction is equal to the total current flowing out
• The conservation of charge states that charge cannot be created or destroyed
• The mathematical expression for the conservation of charge is $\Delta Q =$$0$
• The conservation of charge states that the total charge in a closed system remains constant
• Charge can be created or destroyed in a closed system.

  False
• What does the conservation of charge principle state about the total charge in a closed system?

  It remains constant
• Kirchhoff's First Law is based on the principle of conservation of charge.


  True
• In a series circuit, the total current is equal to the current through each component.


  True
• The total resistance in a series circuit is calculated by adding the individual resistances, such as R_{total} = R_{1} + R_{2} = 2 + 4 = 6 \text{ ohms}</latex>, which equals 6 ohms.
• In a parallel circuit, the total current supplied by the battery is equal to the sum of the currents through each parallel resistor.

  True
• What is the primary application of the formula for total current in a series circuit?

  To find current through components
• What does $I_{total}$ represent in the formula for Kirchhoff's First Law in parallel circuits?


  Total current from battery
• The current through a 3-ohm resistor connected to a 12V battery in a parallel circuit is 4 amps

  True
• The current through R2 in the example circuit is 4 amps


  True
• The formula for Kirchhoff's First Law in parallel circuits is I_{total} = I_{1} + I_{2} + ... + I_{n}</latex>
• Mathematically, Kirchhoff's First Law is expressed as \sum I_{\text{\in}} = \sum I_{\text{out}}
• The conservation of charge principle states that the total charge in a closed system remains constant over time
• In a capacitor charging circuit, through which component do electrons move from the battery to the capacitor?

  Resistor
• The current in a series circuit is uniform at every point.


  True
• The total current entering a junction in a parallel circuit is equal to the sum of the currents in each branch.


  True
• Kirchhoff's First Law in parallel circuits states that the total current into a junction equals the sum of currents in each branch
• The conservation of charge principle states that charge cannot be created or destroyed.


  True
• Kirchhoff's First Law applies to all electrical circuits.

  True
• The net charge at a junction in a circuit cannot change over time.

  True
• In a capacitor charging circuit, the total charge remains constant due to the conservation of charge.


  True
• The conservation of charge principle states that the total electric charge in a closed system remains constant over time
• In a capacitor charging circuit, electrons move from the battery to the capacitor through the resistor
• What is the current like at every point in a series circuit according to Kirchhoff's First Law?

  It is the same
• In a parallel circuit, the total current is the sum of the currents through each branch
• The formula for total current in a series circuit is $I_{total} =$$I_{1} +$$I_{2} +$$... +$$I_{n}$


  False
• The mathematical expression for Kirchhoff's First Law in parallel circuits is $I_{total} =$$I_{1} +$$I_{2} +$$... +$$I_{n}$


  True
• What is the current through a 2-ohm resistor connected to a 12V battery in a parallel circuit?

  6 amps
• What is the resistance of R1 in the example circuit diagram?

  2 ohms
• What does Kirchhoff's First Law state for parallel circuits?

  Total current in equals sum of branch currents
• Match the concept with its description:

  Kirchhoff's First Law ↔️ Total current in equals total current out

  Conservation of charge ↔️ Charge cannot be created or destroyed
• What principle is Kirchhoff's First Law based on?

  Conservation of charge
• The conservation of charge principle states that charge cannot be created or destroyed.


  True
• The conservation of charge principle allows charge to be created or destroyed.

  False
• What happens to the current at a junction in a series circuit according to Kirchhoff's First Law?

  It remains constant
• In a parallel circuit, the total current $I_{total}$ is equal to the sum of individual branch currents.