1. Ohmic Resistor Current-Potential Difference Graph
Describe the relationship shown on the graph.
“As **** increases, ####...”
Describe what negative voltage or current mean on the graph.
Diagram of a simple circuit

2. Non-Ohmic Resistor – LED
Current-Potential Difference Graph
For a diode
What does LED stand for?
Describe how the resistance on the graph changes as you change the voltage and current from positive to negative.
Diagram of a simple circuit containing a diode.
Add arrows showing the direction of positive current and negative current.

3. Non-Ohmic Resistor – LDR
What does LDR stand for?
How can you change the resistance of an LDR?
When is it at it’s lowest resistance?
Resistance graph for an LDR
Diagram of a simple circuit containing an LDR with low resistance.
How might we use an LDR? Where could it be useful? (include a picture)

4. Non-Ohmic Resistor – Thermistor
What is a thermistor?
How can you change the resistance of an thermistor?
When is it at it’s lowest resistance?
Resistance graph for an Thermistor
Diagram of a simple circuit containing an Thermistor with high resistance.
How might we use a thermistor in the kitchen? (include a picture)

5. Become an electrical engineer…
Easy
Design a device that uses a LED or LDR or Thermistor.
Explain how your device is useful.
Medium
Design a device that uses any two of; LED, LDR, Thermistor.
Explain how your device works.
Hard
Design a device that includes a LED, LDR and a thermistor.
Explain how your device works and what would happen if the battery was inserted the wrong way round.