# 7.1.2 Cathode-Ray Oscilloscope

### Cathode-Ray Oscilloscope

• A Cathode-Ray Oscilloscope is a laboratory instrument used to display, measure and analyse waveforms of electrical circuits
• An A.C. current on an oscilloscope is represented as a transverse wave. Therefore you can determine its frequency and amplitude
• The x-axis is the time and the y-axis is the voltage (or y-gain) Diagram of Cathode-Ray Oscilloscope display showing wavelength and time-base setting

• The period of the wave can be determined from the time-base This is how many seconds each division represents measured commonly in s div-1 or s cm-1
• Use as many wavelengths shown on the screen as possible to reduce uncertainties
• Dividing the total time by the number of wavelengths will give the time period T (Time taken for one complete oscillation)
• The frequency is then determined through 1/T

#### Exam Tip

The time-base setting varies with units for seconds (commonly ms) and the unit length (commonly mm). Unit conversions are very important for the calculate of the time period and frequency ### Author: Ashika

Ashika graduated with a first-class Physics degree from Manchester University and, having worked as a software engineer, focused on Physics education, creating engaging content to help students across all levels. Now an experienced GCSE and A Level Physics and Maths tutor, Ashika helps to grow and improve our Physics resources.
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