Electricity

• what is a cell

  transform chemical energy into electrical energy

  
• what is a variable resistor

  it slows down the flow of electrons in the circuit. The resistance can be changed.

  
• what is a diode?

  A component that allows the current to flow in One Direction only. This direction is called forward direction.

  
• what is a thermistor

  It’s a temperature dependent resistor. Its resistance decreases temperature increases.

  
• what is a light dependent resistor?

  It’s a resistor that depends on light. It’s resistance decreases when light intensity increases.

  
• what is a fuse

  used for cutting off an electrical current when there is a overload of electricity

  
• what is a resistor?

  It slows down the flow of electrons in a circuit

  
• what is electrical current?

  The rate of flow of charge

  The flow of charge per second

  The flow of electrons
• what is the equation for current?

  current = charge / time
• what is the symbol and unit for charge?

  symbol = Q

  unit = coulombs (C)
• what is the symbol and unit for current?

  symbol = I

  unit = amps (A)
• what is conventional current?

  It’s the opposite to electron current and goes from positive to negative
• what is electron current?

  The actual way electrons flow from negative to positive
• what is voltage/potential difference?

  Energy given to or taken away from one coulomb of charge. measured in volts with a voltmeter
• what is resistance?

  A measure of the opposition to the flow of charge

  Measured in ohms

  A resistor in a circuit slows down the flow of charge
• what is a fixed resistor?

  Fixed resistor slows the current by fixed rate
• what is the equation for resistance?

  Resistance = voltage / current
• what is a ohmic conductor?

  If the IV graph of a conductor looks like a straight line passing through the origin

  directly proportional
• what happens to voltage in a series circuit?

  The voltage across the cell will be split amongst the components
• how do you calculate total resistance in series circuits

  you add all the resistances together
• what happens to current in a parallel circuit?

  Current current from the battery will be shared amongst the loops
• what happens to current in a series circuit?

  It stays the same
• how do you calculate total resistance in a parallel circuit?

  The total resistance is always smaller than the value of the smallest resistor. Adding more resistance in parallel circuits decreases the total resistance.

  e.g Rt<5
• what is the required practical for electricity?

  Investigating how the resistance of a wire depends on its length

  investigate the relationship between current and potential difference for a resistor bulb and diode