Extra TopicsTopic Summary
Topic Summary: I-V Characteristics
Part of I-V Characteristics — GCSE Physics
This topic summary covers Topic Summary: I-V Characteristics within I-V Characteristics for GCSE Physics. Revise I-V Characteristics in Extra Topics for GCSE Physics with 13 exam-style questions and 11 flashcards. This is a high-frequency topic, so it is worth revising until the explanation feels precise and repeatable. It is section 12 of 12 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 12 of 12
Practice
13 questions
Recall
11 flashcards
Topic Summary: I-V Characteristics
Key Terms
- I-V characteristic — graph of current vs voltage for a component
- Ohmic conductor — straight line through origin, constant R
- Threshold voltage — ~0.6 V for diode to start conducting
- Forward bias — direction diode conducts freely
- Reverse bias — direction diode blocks current
- Rectification — converting AC to DC using diode
Graph Shapes
- Resistor: straight line through origin
- Filament lamp: curve through origin, flattening at high V
- Diode (forward): flat then sharp upward curve at ~0.6 V
- Diode (reverse): flat (virtually no current)
Calculating Resistance
- R = V/I (from coordinates of a point)
- NOT from the gradient
- Gradient = I/V = 1/R
- Steeper line = lower resistance
Practical Setup
- Ammeter: in series with component
- Voltmeter: in parallel with component
- Variable resistor: adjusts current
- Reverse supply to get negative values
- Plot V on x-axis, I on y-axis