PhysicsChapter 9: Nature of Science and Physics
Variables and Fair Tests in Physics
A physics investigation still needs one independent variable, one dependent variable, and control variables held still.
Definition
A physics investigation still needs one independent variable, one dependent variable, and control variables held still. Repeats reduce random error. A hypothesis is a testable 'if... then', not a hope. This is the same method idea as chemistry, with metres, seconds, and newtons.
Overview
Design in two sentences:
What You Change and Measure
Independent: stretch of a spring. Dependent: extension. Or independent: mass, dependent: period of a pendulum. Put units on both axes of the graph.
Examples Hooke's law table · Ticker-timer spacing vs time · Current vs pd for a resistor
What You Keep the Same
Same spring, same metre rule, same starting point. An anomaly is a point that does not fit: check the instrument, do not silently rub it out. Precision vs accuracy stay with the measurement chapter.
Examples Same pendulum length when changing mass (if that is the test) · Three timings, then mean · Zero error on the rule
In simple words
A beautiful graph from an unfair test is still wrong. Markers credit the control list as much as the slope.
Key points
- independent
- dependent
- controls
- one change
- one measure
Quick revision
Revision Zone
Review the key facts, formulas and checks before you move on.Variables and Fair Tests in Physics
Sticky Notes · Quick Revision
Core Idea
- A physics investigation still needs one independent variable, one dependent variable, and control variables held still.
Key Points
- independent
- dependent
- controls
Simple Check
- Explain variables and fair tests in physics in your own words and connect it to one chapter example.
How to Answer
- Define the idea, show the main rule or evidence, apply it, and check the final statement.
Common Mistake
- A beautiful graph from an unfair test is still wrong. Markers credit the control list as much as the slope.
FBISE Exam Tip
- Use the exact term, show working where needed, and include units or labelled evidence.
60-second revision
- independent
- dependent
- controls
Did you understand this topic?
Your answer is saved with your learning record. It does not mark the topic as mastered.