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Combined Science: Physics

GCSE · Edexcel · higher

QuestionsFlashcards

Expressing Quantities & SI Units
- Units & Prefixes
  7
- Conversions & Standard Form
  7

Atomic Structure
Radioactive Decay
Dangers of Radiation
- Dangers of Radiation
  5
- Contamination & Irradiation
  5

Electrical Components Flashcards

All 6 cards in this deck

Describe the current–potential difference graph for a fixed resistor at constant temperature.: A straight line through the origin — current is directly proportional to p.d., so the resistance is constant.
What happens to the resistance of a filament lamp as the current through it increases?: It increases, because the filament gets hotter; the I–V graph curves, becoming less steep.
How does the current through a diode depend on the direction of the potential difference?: Current flows in one direction only; in the reverse direction the resistance is very high and the current is almost zero.
How does the resistance of a light-dependent resistor (LDR) vary with light intensity?: It decreases as the light intensity increases (the resistance is high in the dark).
True or false? The resistance of an NTC thermistor increases as its temperature rises.: False. The resistance of an NTC thermistor decreases as its temperature rises.
For lines through the origin on an I–V graph, what does a steeper line show about a component's resistance?: A lower resistance: more current flows for each volt, because resistance equals 1 ÷ gradient.