CIRCUIT BASICS

• Current can be calculated using Ohm's law, which states that V=IR
• The unit of current is amps (A)
• Potential difference is:


  Force that drives electrons

  Measure in volts

  Pd is provided by Battery/cll

  Called V
• Resistance iS:

  The resistance that resists the flow of electrons

  Is measured in Ohms

  Called R
• Which way around the circuit does current flow

  Positive to negative even though it is wrong.
• The current that flows positive to negative is called what?

  Conventional current
• Total charge can be calculated using what equation

  Q=It

  Q(charge flow in Columbus)

  I(current in Amps)

  t(time in seconds)
• What is Charge measured in?

  Coloumbs C
• What is Charge?

  Total current that has flowed through a circuit or conductor in a certain period of time.
• What is current

   Current is the flow of electrons around the circuit, measured in Amps and is called I in equations.
• What does Potential difference do? (v)

  It creates Potential difference and pushes the electrons around the circuit. Pushes Current basically.
• Some Circuit equations

  V=E/Q Q=coulombs which is charge

  Q=It
• What is Measured in Ohms

  Resistance
• Laws for series circuit

  Total PD is shared between all components

  Current is the same everywhere

  Total resistance= sum of all resistances
• In a series circuit , if resistors are identical total V must be shared equally, if not the bigger resistor takes a bigger share of the V.
• Parallel circuit laws

  Pd for each branch = PD of battery

  Current is SPLIT between branches

  Adding more resistors REDUCES the total resistance
• Equation for Power / volts/ current

  P=IV

  or P=I^2 R