Electricity

  • Hold still please
    problem

    Hold still please

    Age
    16 to 18
    Challenge level
    filled star empty star empty star
    Can you arrange a set of charged particles so that none of them start to move when released from rest?
  • Placeholder: several colourful numbers
    problem

    Resistance

    Age
    16 to 18
    Challenge level
    filled star filled star filled star
    Find the equation from which to calculate the resistance of an infinite network of resistances.