ConceptConceptDocsDocuments

Edexcel IGCSE Physics Investigation Variables

Practise Edexcel IGCSE Physics investigation variables by identifying what changes, what is measured and what must be controlled in practical methods.

Syllabus
Issue 4 (2024)
Course
Physics 4PH1

Exam points

  • Identify the independent and dependent variables from the described investigation.
  • Give control variables that should be kept the same to make the investigation fair.
  • Complete a variable table for an investigation method, including measured counts or readings.

Independent, dependent and control variables question 1

[Maximum number: 2]

A student uses this apparatus to investigate how the efficiency of an electric motor varies with its input voltage.

Figure for Question Independent, dependent and control variables question 1 — Edexcel IGCSE Physics

This is the student's method.
- connect the electric motor to a d.c. power supply and a joulemeter
- attach a 1.0 kg mass to the electric motor using a length of string
- set the voltage of the power supply to 10 V and switch on the power supply
- switch off the power supply when the mass has been lifted through a distance of 50 cm
- record the input energy to the motor from the joulemeter
- calculate the energy transferred to the gravitational store of the mass
- calculate the efficiency of the motor

The student repeats this process, setting the power supply to a different voltage each time.

Give two control variables for the investigation.

1

2

All question bank results loaded