Resistors

• What is a light dependent resistor (LDR)?

  A component that changes its resistance based on light intensity
• How does the sensor in a light dependent resistor react?

  It reacts to light by changing its resistance
• What does the circuit symbol for an LDR look like?

  A rectangle in a circle with arrows indicating light
• What happens to the resistance of an LDR as light intensity increases?

  The resistance decreases
• How is the IV graph for an LDR plotted?

  • Potential difference across the LDR on the horizontal axis
  • Current through the LDR on the vertical axis
• What does a straight line through the origin on an IV graph indicate for an LDR?

  It indicates that the LDR acts as an ohmic conductor with constant resistance
• How does the steepness of the IV graph relate to the resistance of the LDR?

  Steeper graphs indicate lower resistance
• What happens to the IV graph of an LDR when light intensity is increased?

  The graph becomes steeper, indicating lower resistance
• In what applications are LDRs commonly used?

  • Security lights that activate in darkness
  • Smartphone screens that adjust brightness based on surroundings
• Why might an LDR be useful in a security light?

  It activates the light when it is dark
• How do smartphone screens utilize LDRs?

  They adjust brightness based on surrounding light intensity
• What acronym is often used to refer to a light dependent resistor?

  LDR
• What is the significance of knowing how an LDR works for exams?

  You may need to explain its usefulness in a given device
• What features does the Smart Learning platform offer for GCSE revision?

  • Interactive quizzes
  • Easy-to-follow videos
  • Motivation from an AI tutor