What Causes the Amplitude Increase on an Oscilloscope When Touching the Lead?

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Touching the oscilloscope lead increases the amplitude of the displayed wave due to the body's interaction with electromagnetic signals in the environment, typically at 50 Hz or 60 Hz from electrical outlets. The body acts as an antenna, picking up these signals and transferring them to the oscilloscope. This phenomenon highlights the oscilloscope's ability to detect voltage changes, even from invisible sources. The resulting wave displayed is a representation of these captured signals. Understanding this interaction can clarify the oscilloscope's function and the nature of the signals it detects.
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Hi PF, it's been a long time since I've posted on here. I have a lab due soon and it was regarding oscilloscopes. This isn't really a homework problem so I'm not using the template...

Anyways, when I held the input lead in my hand, the amplitude of the wave displayed on the screen got much larger. I can't think of a reason why that would be. TBH, I still don't fully understand the concept of the oscilloscope. I understand that it detects voltage and graphs it as a function of time. But where is this mysterious voltage coming from when I touch the lead? And why is it even a wave?

Thanks in advance for your help.
 
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You are surrounded by electromagnetic signals (at either 50 Hz or 60 Hz), due to the electricity powering the outlets in the room you are in.

Your body acts like an antenna for these signals. By touching the oscilloscope lead, this signal is displayed on the oscilloscope.
 
Thanks Redbelly. I suspected it had to do with some antenna affect. It's still confusing though... it's so hard for me to understand things when they're invisible.
 
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