Uses of OscilloscopeCopy

Cheat Sheet: 4.6 Uses of an Oscilloscope (O Level / IGCSE Physics)

1. Use of an Oscilloscope to Display Waveforms

• An oscilloscope is used to visualise electrical signals by displaying waveforms on a screen.
• The vertical axis (Y-axis) represents voltage.
• The horizontal axis (X-axis) represents time.
• Common waveforms:
  • d.c. supply → straight horizontal line
  • a.c. supply → sine wave (alternating positive and negative)

2. Measuring with an Oscilloscope

A. Measuring Potential Difference (Voltage)

• Use the Y-gain setting (volts per division).
• Count how many vertical divisions the wave spans from peak to trough.
• Calculate peak-to-peak voltage:

Vpp = (Vertical divisions) × (Y-gain in V/div)

• Calculate peak voltage:

Vpeak = (1/2) × Vpp

B. Measuring Time and Frequency

• Use the timebase setting (seconds per division).
• Count how many horizontal divisions one complete wave occupies.
• Calculate time period (T):

T = (Horizontal divisions) × (Timebase in s/div)

• Calculate frequency (f):

f = 1 / T

Key Units

• Y-gain: volts/div
• Timebase: seconds/div
• Frequency: hertz (Hz) = 1/s
• Voltage: volts (V)
• Time: seconds (s)