Circuits and Resistance

• What should you be able to determine by the end of the video?

  Total resistance of resistors in series
• How do you calculate the current in a circuit?

  Divide potential difference by resistance
• What is the potential difference across the 100 ohm resistor?

  5 volts
• What is the current flowing in the circuit with a 100 ohm resistor and 5 volts?

  0.05 amp
• What happens to the current in resistors in series?

  It passes through each resistor in turn
• What is the total resistance of a 100 ohm and a 50 ohm resistor in series?

  150 ohms
• What is equivalent resistance?

  Replacement of multiple resistors with one
• What is the current in a circuit with a potential difference of 20 volts and total resistance of 150 ohms?

  0.13 amp
• What is the total resistance of a 20 ohm, 15 ohm, and 10 ohm resistor in series?

  45 ohms
• What is the potential difference across resistors with a total resistance of 45 ohms and a current of 0.22 amp?

  10 volts
• What is the total resistance of a 200 ohm and a 75 ohm resistor in series?

  275 ohms
• How do you calculate the potential difference in a circuit?

  Multiply resistance by current
• What is the total resistance of two resistors in parallel compared to the smallest resistor?

  Less than the smallest individual resistor
• Why does total resistance decrease in parallel circuits?

  More pathways for current to flow
• What happens to the current when resistors are in parallel?

  More total current flows through the circuit
• What are the steps to calculate current in a circuit with resistors in series?

  1. Add resistances together.
  2. Use the equation: Current = Potential Difference / Total Resistance.
• What are the key facts about resistors in series and parallel?

  • Series: Total resistance is the sum of resistors.
  • Parallel: Total resistance is less than the smallest resistor.
• How do you calculate potential difference in a circuit?

  • Use the equation: Potential Difference = Resistance × Current.
• What is the difference between equivalent resistance and total resistance?

  • Equivalent resistance: Single resistor replacing multiple resistors.
  • Total resistance: Sum of all resistances in a circuit.