Electricity

• Draw the symbol for a cell

  The cell symbol is two parallel lines. A longer line shows the positive terminal. A shorter line shows the negative terminal

  
• Draw the symbol for a battery

  The symbol for a battery looks like two or more cells put together.

  
• Draw the symbol for a voltmeter

  A voltmeter is represented by the letter V in a circle in a circle, with two emerging lines representing the two points of measurement.

  
• Draw the symbol for an ammeter

  The symbol for an ammeter is a circle with a capital A inside.

  
• Draw the symbol for a bulb/lamp

  A circle with a cross through it

  
• Draw the symbol for a diode

  A triangle with a line across one vertex.

  
• Draw the symbol for a resistor

  A rectangle with no line through it

  
• Draw the symbol for a LED (Light Emitting Diode)

  The symbol for a diode but with two arrows denoting emission.

  
• Draw the symbol for a variable resistor

  A rectangle with an arrow through it diagonally

  
• Draw the symbol for a LDR (Light Dependent Resistor)

  The symbol for a resistor but with two arrows pointing to it.

  
• Draw the symbol for a fuse

  A resistor with a line through it

  
• Draw the symbol for a thermistor

  A resistor with a diagonal line through it

  
• Draw the symbol for an open switch

  A line on an angle away from the normal line
• Draw the symbol for a closed switch

  The line stays connected and in line with the rest of the circuit

  
• What is needed for charge to flow through a closed circuit?

  A source of potential difference e.g a cell
• State the units of potential difference

  Volts/V
• Name the component used to measure potential difference

  Voltmeter
• What is a battery?

  Two or more cells
• Name three sources of potential difference

  • cell
  • battery
  • power pack
• Define potential difference

  The work done per unit charge
• What must a circuit be in order for charge to flow?

  Complete
• How must a voltmeter be connected in a circuit?

  In parallel across the component
• State the units of current

  Amps/A
• Name the component used to measure current

  Ammeter
• How must an ammeter be connected in a circuit?

  In series
• Define current

  The rate of flow of charge
• State the direction of conventional current

  From positive to negative
• The equation that links charge, current and time

  charge = current x time
• State the units of charge

  Coulomb/C
• Define resistance

  A property of electrical components that opposes the flow of charge
• State the units of resistance

  Ohms/Ω
• State Ohm's law

  Current is directly proportional to current at a fixed temperature
• What is an ohmic conductor?

  A component that follows Ohm's law
• State two examples of an ohmic conductor

  • wire
  • fixed resistor
• State two examples of non-ohmic conductors

  • filament bulb
  • diode
• The equation that links potential difference, current and resistance

  Potential difference = current x resistance
• What is a series circuit?

  A circuit where the components are in one complete loop
• What is a parallel circuit?

  A circuit where the components are in more than one loop (branch)
• Draw the I/V graph for an ohmic conductor

  Straight diagonal line that passes through the origin

  
• Draw the I/V graph for a filament lamp

  Curved line that passes through the origin