Current, voltage, and resistance in parallel

• What is a parallel circuit?

  A circuit with multiple paths for electricity
• If the voltage source is $5 V$ and the total current is $0.2 A$, what is the total power dissipated by the circuit?


  $1 W$
• How does electricity flow in a parallel circuit?

  Electricity has multiple paths to follow
• How would you draw a simple parallel circuit with two resistors connected to a 12V battery?

  Connect resistors in parallel to the battery
• What happens to the voltage across each bulb in a parallel circuit with a 12V power source?

  • Each bulb receives 12V
  • Voltage remains consistent across all branches
• What does it mean that voltage remains the same in parallel circuits?

  Each component receives the same voltage
• What will the voltage be measured at each part of a parallel circuit?

  It will be the same as the source voltage
• If each bulb has a resistance of $10 \Omega$ and the voltage source is $5 V$, what is the current flowing through each bulb?


  $0.25 A$
• What ensures equal voltage distribution in parallel circuits?

  The voltage source provides consistent voltage
• What happens to the total current in a parallel circuit?

  It splits between different branches
• How does the diagram of a parallel circuit differ from a series circuit?

  It shows multiple paths for electricity flow
• What circuit components are represented by the labels 1, 2, 3 and 4?

  • 1: Wire
  • 2: Wire
  • 3: Wire
  • 4: Bulb
• How does current flow in a parallel circuit?

  Through each path separately
• What happens to the total current in the circuit if one of the bulbs burns out?

  Total current decreases
• What does the label I(R2.nA) represent in the circuit diagram?

  The current flowing into R2
• In the circuit diagram, what do the labels I(V1.nA) and I(V1.nB) represent?

  Current flow into and out of V1
• If the ammeter measures 0.2A in a parallel circuit, what does this represent?

  The combined current through both light bulbs
• What are the first three steps to run a simulation in CircuitLab?

  • Click to open the circuit.
  • Click "Simulate".
  • Click "Run DC Solver".
• What are the key features of a parallel circuit?

  • Multiple paths for electricity
  • Independent connections for components
  • Current splits among paths
  • Equal voltage across all components
• What is the voltage of the battery in the circuit?

  9 V
• What are the main components in the circuit?

  • Voltage source (V1)
  • Resistors (R1, R2, R3)
  • LED (D1)
  • BJT (Q1)
• What are the main equations governing parallel circuits?

  • Total Current: $I_{total} =$$I_{1} +$$I_{2} +$$I_{3}$
  • Source Voltage: $V_{source} =$$V_{1} =$$V_{2} =$$V_{3}$
  • Total Resistance: $\frac{1}{R_{total}} =$$\frac{1}{R_{1}} +$$\frac{1}{R_{2}} +$$\frac{1}{R_{3}}$
• What is the purpose of the resistors in this circuit?

  • The resistors limit the current flow in the circuit
  • They control the voltage drop across different parts of the circuit
  • They allow the circuit to function as intended by regulating the current
• What is the model number of transistor Q1?

  2N3904
• What is the model number of the LED D1?

  LTL-307EE
• What is the total current in the circuit with a 9V source and resistors of 10000 Ω, 2000 Ω, and 1000 Ω?

  $0.01545 A$
• What are the steps to solve for total resistance, voltage, and current in a parallel circuit?

  1. Calculate total resistance using $\frac{1}{R_{total}} =$$\frac{1}{R_1} +$$\frac{1}{R_2} +$$\frac{1}{R_3}$
  2. Determine voltage across each branch (equal to source voltage)
  3. Find branch currents using $I =$$\frac{V}{R}$
  4. Sum branch currents for total current
• How does the behavior of voltage in parallel circuits differ from that in series circuits?

  Voltage is the same in parallel, varies in series
• In the circuit diagram, what does the ground symbol represent?

  The reference point for zero voltage
• Why does total resistance decrease in parallel circuits?

  Electricity has more paths to flow through
• How do three resistors in parallel affect current flow?

  • Create multiple branches for current flow
  • Allow more current to pass through
  • Result in lower total resistance
• What is the voltage of the battery in the circuit?

  9 V
• What is the resistance value of resistor R1?

  10 kΩ
• How does the arrangement of the resistors in parallel affect the overall resistance of the circuit?

  • The total resistance of resistors in parallel is less than the smallest individual resistance
  • The current divides among the parallel branches, with more current going through lower resistance paths
  • The voltage drop is the same across all parallel branches
• If the source voltage is 5V, what is the voltage across each branch?

  5V across each branch
• How does the behavior of resistance in parallel circuits differ from series circuits?

  Resistance decreases in parallel, increases in series
• How would changing the resistance values of the resistors affect the current flow in the circuit?

  • Increasing the resistance would decrease the current flow
  • Decreasing the resistance would increase the current flow
  • The current flow is inversely proportional to the resistance values
• What is the total resistance in a parallel circuit compared to the smallest individual resistance?

  Total resistance is less than the smallest resistance
• What is the resistance value of resistor R2?

  2 kΩ
• What is the significance of having multiple branches in a parallel circuit?

  It allows for increased current flow