This exam tips covers Exam Tips for 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 topic appears regularly enough that it should still be part of a steady revision cycle. It is section 11 of 12 in this topic. Treat this as a marking guide for what examiners are looking for, not just a fact list.
💡 Exam Tips for I-V Characteristics
🎯 Common Question Types:
- Sketch I-V graph for resistor, lamp, or diode [2 marks each]
- Explain the shape of the filament lamp I-V curve [3-4 marks]
- Calculate resistance from coordinates on I-V graph [2 marks]
- Describe the method for the I-V characteristics practical [4-5 marks]
- Explain how a diode works (forward/reverse bias) [3 marks]
📝 Key Command Words:
- Sketch — draw a clearly labelled diagram, no need for scale but correct shape essential
- Describe — say what the graph shows, not why
- Explain — give the physics reason for the shape
- Calculate — show V/I at a stated point, not gradient
- State — brief answer only, no working needed
⚠️ Common Mistakes to Avoid:
- Using gradient to calculate resistance — use R = V/I from coordinates
- Drawing the filament lamp as a straight line — it must be a curve
- Putting ammeter in parallel — it must always be in series
- Forgetting the diode barely conducts below threshold voltage (~0.6 V)
- Not drawing the I-V graph with current on the y-axis and voltage on the x-axis
Practice questions for I-V Characteristics
What does an I-V characteristic graph show for a component?
Explain why the I-V graph for a filament lamp is not a straight line.
Quick recall flashcards
What is a diode used for?
Converting AC to DC (rectification), because it only conducts in one direction
What is an ohmic conductor?
A component where current is directly proportional to voltage at constant temperature. The I-V graph is a straight line through the origin