Learning objective

Define and utilize the terms principal axis, principal focus (focal point), and focal length.

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Exam focus

Cambridge IGCSE Combined ScienceWavesCore content

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Quick explanation

This point belongs to Light, especially Light outcomes.
You need to be able to define and utilize the terms principal axis, principal focus (focal point), and focal length.
The key ideas to know are Define and Describe.
Use the linked flashcards and practice questions to check recall, then practise applying the idea in an exam-style answer.

Key concepts

DefineDescribe

Why it matters

This objective helps connect Light outcomes to exam-style questions, flashcards, and revision notes for Light.

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Flashcards10 linked cards

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Practice Questions7 linked questions

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Paper 3Theory (Core)3 marks

Description

In optics, the principal axis, principal focus, and focal length are key concepts that describe how lenses and mirrors function.

a
Define the terms principal axis, principal focus, and focal length.
Your answer
Aim for approximately 3 distinct marking points.
[3]

Revision notestopic notes

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