ElectricityDeep Dive

What Affects the Resistance of a Wire?

Part of Resistance & Ohm's Law · GCSE GCSE Physics revision

This deep dive covers What Affects the Resistance of a Wire? within Resistance & Ohm's Law for GCSE Physics. Revise Resistance & Ohm's Law in Electricity for GCSE Physics with 16 exam-style questions and 30 flashcards. This topic shows up very often in GCSE exams, so students should be able to explain it clearly, not just recognise the term. It is section 4 of 16 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 4 of 16

Practice

16 questions

Recall

30 flashcards

🔧 What Affects the Resistance of a Wire?

Four factors:

  • Length — longer wire = more resistance (R ∝ L)
  • Cross-sectional area — thicker wire = less resistance (R ∝ 1/A)
  • Material — different materials have different resistivities
  • Temperature — for metals, hotter = more resistance

Why length increases resistance:

  • Electrons must travel further through the material
  • More collisions with metal ions along the way
  • More opposition to flow overall

Why thickness decreases resistance:

  • More pathways for electrons to flow side-by-side
  • Like a wider road with more lanes — less congestion
  • Less crowded = easier flow

Keep building this topic

Read this section alongside the surrounding pages in Resistance & Ohm's Law. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Resistance & Ohm's Law

Which of the following best describes electrical resistance?

  • A. The amount of charge flowing past a point per second
  • B. The opposition to the flow of current in a circuit
  • C. The energy transferred per unit charge by the source
  • D. The rate at which electrical energy is transferred
1 markfoundation

Explain what is meant by an ohmic conductor.

2 marksstandard

Quick Recall Flashcards

Unit of resistance?
Ohm (Ω)
Ohm's Law equation?
V = IR where V = voltage (V), I = current (A), R = resistance (Ω)

16 questions on Resistance & Ohm's Law — practise free

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