current, pd and resistance

• What is electrical charge measured in?

  Coulombs
• What is the symbol for coulombs?

  Capital C
• What does a current of 1 ampere signify?

  1 Coulomb of charge flowing per second
• What is the electric current equivalent to?

  The rate of flow of electrical charge
• What happens whenever charge flows in a circuit?

  Work is done and energy is transferred
• How is potential difference shared across components in a series circuit?


  Potential difference is shared
• What is the unit of measurement for charge?

  Coulombs
• What is the unit of measurement for current?

  Amperes
• What is the unit of measurement for time used in the charge equation?

  Seconds
• What is the unit of measurement for potential difference?

  Volts
• What is the unit of measurement for energy?

  Joules
• What is the physics symbol for a cell?

  A line with a shorter parallel line
• According to the video, what is a battery?

  Two or more cells connected together
• What is a key point about batteries regarding cell direction?

  Cells must be connected in the same direction
• How is the total potential difference of a battery calculated when cells are connected in series?

  The potential differences of cells add up
• A battery contains two cells, each with a potential difference of 9 volts, but one cell is pointing in the opposite direction; what is the overall potential difference?

  0 volts
• Why does a battery with cells pointing in opposite directions have an overall potential difference of zero?

  The potential differences of the cells cancel out
• A battery has three 9-volt cells, with two pointing in the correct direction and one pointing in the opposite direction; what is the overall potential difference?

  9 volts
• In a battery with some cells oriented correctly and others incorrectly, how does the reversed cell affect the total potential difference?

  It cancels out one of the other cells
• What type of energy does the cell contain in an electric circuit?

  Chemical energy
• In an electric circuit, what is the chemical energy from the cell transferred to?

  Electrical energy
• What is the current in a circuit?

  A flow of electrons
• When electrons pass through a component like a lamp, what does electrical energy transfer to?

  Light and thermal energy
• What quantity do we use to work out the energy transfers involved in a circuit?

  Potential difference
• If a cell has a potential difference of 9 volts, what does this tell us about the energy carried by the current?

  The current carries 9 joules per coulomb
• If the potential difference across a lamp is 9 volts, what does it tell us about the energy transfer?

  All electrical energy is transferred by the lamp
• What causes components to transfer energy in a circuit?

  Resistance
• What happens as electrons move through a metal wire in a circuit?

  They collide with atoms
• When electrons collide with atoms in a metal, what form of energy is electrical energy transferred into?

  Thermal energy
• What does resistance tell us about driving a current through a component?

  Potential difference required
• What is the interpretation of resistance in terms of energy and charge?

  Energy required to push a coulomb of charge
• What is the unit for resistance?

  Ohm
• What is the symbol for the ohm?

  Ω
• If a lamp has a current of 1 ampere and a potential difference of 1 volt, what is its resistance?

  1 ohm
• If a lamp has a current of 1 ampere and a potential difference of 10 volts, what is its resistance?

  10 ohms
• What happens to the total resistance when resistors are in series?

  Resistors in series add together
• Why do resistors in series add together?

  The current passes through each resistor in turn
• What is the term for the single resistance that could replace multiple resistors in series?

  Equivalent resistance
• What is the relationship between the total resistance and individual resistors in parallel?

  Total resistance is less than the smallest
• If you have a 150 ohm and a 200 ohm resistor in parallel, what is true of the total resistance?

  It will be less than 150 ohms