Measurement and Uncertainty for IP Physics: From Sig-Figs to Spreadsheet Graphs

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30 Nov 2025, 00:00 Z

Reviewed by

Chee Wei Jie·Academic Advisor (Physics)

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Q: What does Measurement and Uncertainty for IP Physics: From Sig-Figs to Spreadsheet Graphs cover?
A: How to align IP Physics measurement and uncertainty skills to SEAB's 2026 syllabuses, including sig-fig rules, uncertainty propagation, and spreadsheet-based analysis.

TL;DR - New syllabus = new marks.
Quote instruments to the correct significant figures, report uncertainties as $\pm \frac{1}{2}$ least-division, and round calculated quantities to the smallest-sf raw datum.
Master absolute → fractional → percentage error conversions; propagate by addition for x / ÷, by sum of percentages for powers.
In H2 Physics (9478), Paper 4 (Practical) can include spreadsheet-based data processing (graphs, trendlines, gradients and areas).
Try the 20-s pendulum timing lab below; analyse your data with Sheets/Excel and you will have practised every assessed skill in one evening.

Need more structured drills? Follow the weekly diagnostics inside our IP Physics hub so measurement practice lines up with the rest of your upper-sec revision.

1 Why measurement & uncertainty just became high-stakes

In the 2026 H2 Physics (9478) syllabus, Paper 4 (Practical) can include data analysis where candidates are required to process and analyse data using spreadsheet software.

At O-Level Physics (6091), practical work still rewards accurate measurement, correct units and appropriate significant figures - the syllabus explicitly warns that misuse of units/significant figures is liable to be penalised.

Instrument	Least division / resolution	Raw reading rule	Example
Metre rule	$1 \space \pu{mm}$	$\pm \space 0.5 \space \pu{mm}$	$42.0 \space \pu{cm} \pm \space 0.05 \space \pu{cm}$
Thermometer	$1 \space \pu{^\circ C}$	$\pm \space 0.5 \space \pu{^\circ C}$	$23.0 \space \pu{^\circ C} \space \pm \space 0.5 \space \pu{^\circ C}$
Digital stopwatch	$0.01 \space \pu{s}$	quote all decimals	$12.37 \space \pu{s}$

Symbol	Definition
$\Delta x$	Absolute uncertainty (same unit as $x$ )
$\frac{\Delta x}{x}$	Fractional uncertainty (no units)
$\frac{\Delta x}{x}\times100\%$	Percentage uncertainty $\%$

Trial	$t_{20}$ / $\pu{s}$	$T = t_{20}/20$ / $\pu{s}$
1	31.20	1.560
…	…	…

Measurement and Uncertainty for IP Physics: From Sig-Figs to Spreadsheet Graphs

1 Why measurement & uncertainty just became high-stakes

2 Reading instruments & recording to the right sig-figs

2.1 Analogue versus digital

2.2 Sig-fig decision tree

3 Absolute, fractional & percentage uncertainty

Quick drill

4 Spreadsheet skills now examinable

5 Mini-Lab: Timing a pendulum with your phone & Sheets

5.1 Setup

5.2 Data collection

5.3 Spreadsheet crunch

6 Nine examiner-liked habits to lock in marks

7 Quick self-check

Practice Quiz

8 Further reading

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