5.3 Circuits

• What are the three fundamental electrical quantities?

  Current, potential difference, resistance
• Potential difference is measured in volts.


  True
• What is the formula for Ohm's Law?

  $V =$$IR$
• What are the three key electrical quantities?

  Current, potential difference, resistance
• Ohm's Law states that potential difference is directly proportional to current
• Electrical power is measured in watts.


  True
• What is the same through all elements in a series circuit?

  Current
• In a series circuit with resistors of 10 Ω and 20 Ω connected to a 12V supply, the current is 0.4 A
• The total resistance in a parallel circuit is always less than the smallest individual resistance.


  True
• Arrange the steps to calculate current in a series circuit:

  1️⃣ Calculate the total resistance

  2️⃣ Use Ohm's Law to find the current

  3️⃣ Substitute the values into the formula
• The total resistance in a series circuit is the sum of individual resistances
• What happens to the current in a parallel circuit?

  Current divides among branches
• The potential difference is the same across all components in a parallel circuit.


  True
• Match the electrical quantity with its unit:

  Current ↔️ Ampere

  Potential Difference ↔️ Volt

  Resistance ↔️ Ohm
• Electrical power is calculated using the formula P = VI
• The total resistance in a series circuit is less than the smallest individual resistance.

  False
• The potential difference is distributed across components in a parallel circuit.

  False
• In a parallel circuit, the resistance is less than the smallest individual resistance because current flows through multiple paths
• The total resistance in a parallel circuit is less than the smallest individual resistance.


  True
• What is the current through a 20 Ω resistor in a parallel circuit connected to a 12 V supply?

  0.6 A
• In a parallel circuit, the potential difference is the same across all components.

  True
• What is the current through a 10 Ω resistor in a parallel circuit connected to a 12 V supply?

  1.2 A
• The total current in a parallel circuit is the sum of the currents through each branch.


  True
• How are series resistors combined to calculate equivalent resistance?

  By adding their resistances
• The equivalent resistance of two 20 Ω resistors in parallel is 10 Ω.


  True
• In a combination circuit, if R₃ = 30 Ω and R₂ = 20 Ω, what fraction of the total current flows through R₃?

  20/50
• What is the total resistance of two resistors in series with values 10 Ω and 20 Ω?

  30 Ω
• In a series circuit, the current is the same throughout the circuit.


  True
• What is the formula for calculating total resistance in a series circuit?

  R_total = R₁ + R₂ + ... + Rₙ
• In a parallel circuit, the total resistance is always less than the smallest individual resistance
• What is the formula for calculating total resistance in a parallel circuit?

  1/R_total = 1/R₁ + 1/R₂ + ... + 1/Rₙ
• The formula for calculating total resistance in a series circuit is R_total = R₁ + R₂ + ... + Rₙ

  True
• In parallel circuits, the total resistance is less than the smallest individual resistance
• What is the total resistance of two resistors in parallel with R₁ = 10 Ω and R₂ = 20 Ω?

  6.67 Ω
• What are the three key electrical quantities?

  Current, voltage, resistance
• Match the electrical quantity with its unit:

  Current ↔️ Ampere

  Potential Difference ↔️ Volt

  Resistance ↔️ Ohm
• What does Ohm's Law state?

  V = IR
• Electrical power is calculated using the formula P = VI
• In a series circuit, the current is the same through all elements.


  True
• In a parallel circuit, the potential difference is the same across all components.


  True