Question 21
HA musician plays a single note into a moving-coil microphone. The microphone is connected to an oscilloscope.
The Figure shows the trace on the oscilloscope.
Figure
a.[3]
Calculate the frequency of the note.
Use the equation
frequency=1time period\displaystyle \text{frequency} = \frac{1}{\text{time period}}frequency=time period1
b.[3]
The musician plays the same note more loudly.
Describe and explain how the trace would change.
c.[2]
Explain why the potential difference produced by the microphone keeps changing direction.
13.1 Inducing a current Questions
92 exam-style questions on Edexcel GCSE Physics 13.1 Inducing a current, covering 13.1.1 Producing an electric current by induction, 13.1.2 Factors affecting the induced potential difference, 13.1.3 Alternators and dynamos, and 13.1.4 Microphones and loudspeakers. Each one has a worked solution and a mark scheme showing where the marks go.