Series & Parallel Circuits

• What are the two ways of joining electrical components?

  In series and in parallel
• What is a series circuit?

  A series circuit consists of a string of two or more components connected end to end
• What is a parallel circuit?

  A parallel circuit consists of two or more components attached along separate branches of the circuit
• What are the characteristics of a series circuit?

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

  
• 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

  
• How is the total resistance calculated in a series circuit?

  The total resistance is the sum of the resistance of each component

  
• In a parallel circuit, how is the total current related to the currents through the separate components?

  The total current is the sum of the currents through the separate components

  
• What is the potential difference across each component in a parallel circuit?

  The potential difference across each component is the same
• How does the total resistance of two resistors in parallel compare to the smallest individual resistor?

  The total resistance is less than the resistance of the smallest individual resistor
• What happens to the current in a parallel circuit at a junction?

  • Current splits at junctions
  • Some current goes one way, the rest goes another
• Why do electrons behave as they do in a circuit?

  Electrons are physical matter that cannot be created or destroyed
• What is the total resistance when two or more resistors are connected in series?

  The total resistance is equal to the sum of their individual resistances

  
• If two resistors of resistance $R_1$ and $R_2$ are connected in series, what is the formula for total resistance?


  $R =$$R_1 +$$R_2$

  
• What happens to the overall resistance when more resistors are added in series?

  The overall resistance increases
• Why does adding resistors in parallel decrease total resistance?

  Each resistor creates an extra path for charge to flow
• What are the advantages of parallel circuits?

  • Components can be individually controlled
  • If one component fails, others continue to function
• What is a disadvantage of series circuits?

  If one component breaks, all others stop working
• How does the current behave in a series circuit?

  The current is the same at all points

  
• How is the potential difference shared in a series circuit?

  The voltage of the power supply is shared between the components
• What is the relationship between total resistance and individual resistances in a series circuit?

  Two resistors in series will have a larger overall resistance than just one
• What happens to the charge in a parallel circuit?

  The charge has more than one pathway to take
• What is the fundamental concept about circuits regarding changes in current, potential difference, and resistance?

  • Changing one affects all
  • Current, potential difference, and resistance are interrelated
• What defines a direct current (d.c.)?

  A current that is steady and constantly flowing in the same direction
• What is the potential difference across a cell in a d.c. circuit?

  The potential difference is in one direction only
• What are the disadvantages of series circuits?

  • If one component breaks, all stop working
  • Components cannot be controlled separately
• How does the current behave in a d.c. series circuit?

  The current is the same at all points
• How is the potential difference shared in a d.c. series circuit?

  The potential difference of the power supply is shared between the individual components
• What is the formula for calculating resistance in a series circuit?

  $R =$$R_1 +$$R_2 +$$R_3$

  
• What happens to the current if one component in a series circuit fails?

  All components will stop working
• What is the relationship between the number of components and resistance in a series circuit?

  The more components, the higher the number of collisions and resistance
• How does the total resistance in a parallel circuit compare to the resistance of individual components?

  The total resistance is less than the resistance of any individual component

  
• What is the effect of adding more pathways in a parallel circuit?

  It allows more charge to flow overall, leading to smaller overall resistance
• What is the significance of the current splitting at junctions in a parallel circuit?

  It allows for different amounts of current to flow through different branches

  
• What happens to the current in a parallel circuit if one branch is removed?

  The current will still flow through the other branches
• How does the potential difference behave in a parallel circuit?

  The potential difference across each component is the same
• What is the relationship between the total resistance and the number of pathways in a parallel circuit?

  The more pathways there are, the smaller the total resistance
• What is the effect of adding a resistor in series compared to adding it in parallel?

  Adding in series increases total resistance, while adding in parallel decreases it

  
• What is the significance of the fixed terminals in a d.c. power supply?

  The fixed terminals indicate the direction of current flow
• How does the potential difference behave in a d.c. circuit powered by cells or batteries?

  The potential difference is in one direction only
• What happens to the components in a series circuit if one component fails?

  All components will stop working