2.2 Series & Parallel Circuits

• What are the two ways of joining electrical components?

  In series and in parallel
• What does a series circuit consist of?

  A string of components connected end to end
• How is a parallel circuit structured?

  Components attached along separate branches
• What are the characteristics of series circuits?

  • Current is the same at all points
  • Total potential difference is shared
  • Total resistance is the sum of individual resistances

  
• What happens to the current in a series circuit?

  The current is the same at all points
• How is the total potential difference in a series circuit calculated?

  It is shared between the components

  
• How is total resistance calculated in a series circuit?

  It is the sum of each component's resistance
• If a battery is marked 12 V in a series circuit with two lamps, what is the potential difference across each lamp?

  6 V across each lamp

  
• If each lamp in a series circuit has a resistance of R, what is the total resistance?

  2R
• What are the characteristics of parallel circuits?

  • Total current is the sum through components
  • Potential difference across each component is the same
  • Total resistance is less than the smallest resistor

  
• How does current behave in a parallel circuit?

  It splits at junctions

  
• If a battery is marked 12 V in a parallel circuit, what is the potential difference across each lamp?

  12 V across each lamp

  
• What happens to the total resistance when resistors are connected in parallel?

  It decreases
• Why does the total resistance decrease in a parallel circuit?

  More pathways allow more charge to flow
• What is the total resistance of two resistors in parallel compared to the smallest individual resistor?

  It is less than the smallest resistor
• What happens to the current in each branch of a parallel circuit?

  It may not split equally

  
• What happens to the charge when electrons reach a junction?

  Some go one way, others go another
• What is the fundamental concept about current in a circuit?

  It cannot be created or destroyed
• What are the advantages of parallel circuits?

  • Components can be individually controlled
  • If one component fails, others continue to work
• What is the total resistance when resistors are connected in series?

  It is the sum of their resistances
• How does adding resistors in series affect overall resistance?

  It increases the overall resistance
• What is the total resistance of two resistors R1 and R2 in series?

  $R =$$R_1 +$$R_2$

  
• What is the total resistance of two resistors R1 and R2 in parallel?

  $\frac{1}{R} =$$\frac{1}{R_1} +$$\frac{1}{R_2}$

  
• Why does adding a resistor in parallel reduce total resistance?

  It creates an extra path for charge flow
• What is direct current (d.c.)?

  A steady current flowing in one direction

  
• What is the relationship between current, potential difference, and resistance in a circuit?

  • Changing one affects the others
  • Current, potential difference, and resistance are interconnected
• What is the potential difference across a cell in a d.c. circuit?

  It is in one direction only
• What type of power supply produces direct current?

  Electric cells or batteries
• What is a series circuit?

  A loop of components connected to a power supply

  
• What are two disadvantages of series circuits?

  Failure of one component stops all
• How is the potential difference shared in a series circuit?

  It is divided among the components
• How does the current behave in a series circuit?

  It remains the same at all points
• What happens to the total resistance when more components are added in series?

  It increases
• Why does the charge experience more collisions in a series circuit?

  It has to push through multiple components
• What is the total resistance of two resistors in parallel compared to one?

  It is smaller than one resistor
• How does the number of pathways affect the charge in a parallel circuit?

  More pathways reduce charge in each path
• What is the effect of adding a resistor in series?

  It increases total resistance
• What is the relationship between current and resistance in a parallel circuit?

  Higher current leads to lower resistance
• How does the addition of resistors in parallel affect the overall circuit?

  It allows more charge to flow overall

  
• What is the significance of the potential difference in a series circuit?

  It determines how voltage is shared