Circuit devices

• What can you create with current and potential difference measurements?

  Sweet graphs
• What do current-potential difference graphs show?

  • How current varies with potential difference
  • Changes in potential difference affect current
• What do linear I-V graphs indicate about current?

  Current is directly proportional to potential difference
• How do different resistors affect I-V graphs?

  They have different slopes
• What happens to temperature when current increases in a filament lamp?

  Temperature of the filament increases
• What does an increasing current in a filament lamp do to resistance?

  Increases resistance
• What direction does current flow through a diode?

  Only in one direction
• What happens to current in the reverse direction through a diode?

  Very little current flows
• What are the characteristics of linear components in I-V graphs?

  • Straight line through the origin
  • Current is proportional to potential difference
• What are the characteristics of non-linear components in I-V graphs?

  • Curved line
  • Current is not proportional to potential difference
• What is the resistance of a linear component at the origin of the graph?

  Equal to the inverse of the gradient
• What happens to resistance as the gradient of the graph decreases?

  Resistance increases
• How can you find resistance from an I-V graph?

  By reading the gradient
• What does the term "LDR" stand for?

  Light Dependent Resistor
• How does an LDR behave in bright light?

  Resistance falls
• How does an LDR behave in darkness?

  Resistance is highest
• What are the applications of LDRs?

  • Automatic street lights
  • Light-sensitive alarms
  • Photography exposure meters
• What is the behavior of resistance in a thermistor with temperature changes?

  Resistance decreases with increasing temperature
• What is a common application of thermistors?

  Temperature sensing devices
• What are the characteristics of thermistors?

  • Temperature-sensitive resistors
  • Resistance varies with temperature
• What is the relationship between current and potential difference in a filament lamp?

  Non-linear relationship
• What happens to the resistance of a thermistor in cold conditions?

  Resistance increases
• What is the effect of light intensity on an LDR?

  Higher light intensity lowers resistance
• What are the applications of thermistors?

  • Temperature control circuits
  • Overheating protection
  • Temperature measurement
• What is the significance of the term "resistance" in electrical components?

  Opposition to current flow
• How does temperature affect the resistance of a thermistor?

  Resistance decreases with temperature increase
• What is the primary function of an LDR?

  To change resistance based on light
• What are the characteristics of LDRs?

  • Resistance decreases with light intensity
  • Used in light-sensitive applications
• What is the primary function of a thermistor?

  To change resistance based on temperature
• What are the characteristics of thermistors?

  • Resistance decreases with temperature increase
  • Used in temperature-sensitive applications
• What is the relationship between current and potential difference in a diode?

  Current flows in one direction only
• What happens to the resistance of a diode in reverse bias?

  Resistance is very high
• What is the effect of temperature on the resistance of a filament lamp?

  Resistance increases with temperature
• What are the applications of diodes?

  • Rectifiers in power supplies
  • Signal demodulation
  • Protection circuits
• What is the primary use of resistors in circuits?

  To limit current flow
• How do resistors affect voltage in a circuit?

  They drop voltage across themselves
• What are the characteristics of resistors?

  • Oppose current flow
  • Used to control voltage and current
• What is the relationship between voltage and current in a resistor?

  Directly proportional
• What happens to current when resistance increases?

  Current decreases
• What are the applications of resistors?

  • Voltage dividers
  • Current limiters
  • Signal processing