Physics

• What is the equation that relates voltage, current, and resistance?


  v = ir
• What does the equation v = ir stand for?

  Potential difference (voltage) equals current times resistance
• If a circuit has a current of 4 amps and a resistance of 2 ohms, what is the voltage?


  8 volts
• How do you find the resistance if you have a 24 volt battery producing a current of 8 amps?


  By rearranging the equation to r = v / i and calculating
• What is the resistance when using a 24 volt battery and a current of 8 amps?


  3 ohms
• What happens to current when voltage increases while resistance remains constant?

  The current increases proportionally
• What is the relationship between voltage, current, and resistance in a circuit?

  • Voltage (v) = Current (i) × Resistance (r)
  • If resistance is constant, increasing voltage increases current proportionally
• What does a graph of current against potential difference look like for circuits with constant resistance?


  It shows straight lines
• What does a steeper line on a current versus potential difference graph indicate?


  A smaller resistor is present, requiring less potential difference for a given current
• What happens to resistance if the temperature increases in a circuit?


  The resistance increases
• Why do higher currents generally cause wires to heat up?


  Because of increased resistance and energy loss as heat
• What are filament lamps and how do they work?


  • Filament lamps contain a thin metal filament
  • Current heats the filament until it emits light
  • Increased current raises resistance, making the curve less steep on a graph
• How does the resistance of a filament lamp change as current increases?

  The resistance increases, causing less current to flow per unit of potential difference
• What are diodes and their function in a circuit?

  • Diodes allow current to flow in one direction only
  • They show current only when potential difference is positive
  • They have high resistance in the reverse direction, preventing current flow
• What happens to current when the potential difference is negative in a diode?


  No current flows
• What type of circuits are being explored in today's video?

  Parallel circuits
• How do parallel circuits treat potential difference, current, and resistance?


  They provide full source potential difference to each component, share current among loops, and lower total resistance with more components.
• What is a characteristic of parallel circuits regarding components?


  Each loop generally contains a single component.
• Why are parallel circuits considered more useful than series circuits?


  Because if one component breaks, the overall circuit remains intact.
• What happens if one light in a parallel circuit blows?


  All other lights will still work.
• What is the relationship between series and parallel circuits in a mixed circuit?


  A mixed circuit can have multiple loops with more than one component in some loops.
• What is the potential difference across each component in a parallel circuit with a 12-volt battery?


  12 volts
• How is current shared in a parallel circuit?


  The current is shared between all loops, adding up to the total current of the circuit.
• If a parallel circuit has two loops with a total of 4 amps flowing, how might the current be distributed?


  It could be 3 amps in the first loop and 1 amp in the second, or 2 amps in each loop.
• What determines how the current splits in a parallel circuit?


  The resistance of the individual components in the circuit.
• How can you visualize the flow of current in a parallel circuit?


  As water flowing down a hill, where more water flows through paths of least resistance.
• What happens to the total resistance of a parallel circuit as more components are added?


  The total resistance decreases.
• Why does adding more loops in parallel decrease overall resistance?


  It increases the options for current flow, making it easier for current to pass through.
• How can the concept of water flow help in understanding parallel circuits?


  It illustrates how current prefers paths of least resistance, similar to water flowing down a hill.
• What is the key takeaway about the relationship between components and resistance in parallel circuits?

  The more components added in parallel, the lower the overall resistance.
• What are the main characteristics of parallel circuits?


  • More than one loop
  • Each loop generally contains a single component
  • Full source potential difference across each component
  • Current is shared among loops
  • Total resistance decreases with more components
• How does the current behave in a parallel circuit with different resistances?


  • Current splits based on resistance
  • Lower resistance loops carry more current
  • Total current is the sum of currents in each loop
• How does adding components in parallel affect the flow of current?


  • Increases options for current flow
  • Makes it easier for current to pass through
  • Decreases overall resistance
• Ek=1/2m x v*2

  What is friction equation