Edexcel IGCSE Physics Graphical and Numerical Forms

Edexcel IGCSE Physics Graphical and Numerical Forms
Edexcel IGCSE Physics syllabusPhysics 4PH1Issue 4 (2024)

Practise Edexcel IGCSE Physics graphical and numerical forms by reading values, describing trends and choosing suitable graph representations.

How this is tested

  • Read a value from a graph, such as distance at a given percentage or operating voltage.
  • Describe graph trends using data, including non-linear reduction or penetration relationships.
  • Explain why a line graph is suitable when the plotted data are continuous.

Question 8(d)(iv)

[Maximum number: 1]

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

Figure for Question 8(d)(iv) — 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.

The table shows the student's results.

Table for Question 8(d)(iv) — Edexcel IGCSE Physics

Using the graph, determine the minimum power supply voltage that will allow the electric motor to operate at maximum efficiency.

voltage = ............ V