An acoustics lab technician is setting up a test circuit to measure how the sound pressure level of a miniature signal transducer (speaker) changes with voltage.
The laboratory's DC power supply only provides discrete, fixed voltage outputs of 1.5 V, 3.0 V, 4.5 V, and 6.0 V.
Describe how the technician could modify the circuit by adding a single standard component to enable them to continuously vary the potential difference across the transducer.
59 exam-style questions on Edexcel GCSE Physics 10.2 Resistance, covering 10.2.1 Current in a circuit and conservation at junctions, 10.2.2 Resistance and variable resistors, 10.2.3 Series and parallel resistance, 10.2.4 I–V characteristics of components, and 10.2.5 LDRs and thermistors. Each one has a worked solution and a mark scheme showing where the marks go.