My dad's old TV! When I switch it off after watching and get my hands closer, my hands' hair gets attached to the screen. And they stick for sometimes! Now, I know how a cathode ray oscilloscope works. It is just the clever use of Hall - Effect . But why does my hair get stuck to the screen? What is the cause? Note, I checked this for my LED TV but it didn't work (I couldn't perceive anything) unknowingly. What's the magic in my old TV??
Answer
Static electricity. The cathode ray tube shoots electrons at the back of the TV screen, which becomes negatively charged. To compensate, and try and maintain electrical neutrality, the front of the screen becomes positively charged (the glass acts as a capacitor).
As you walk across a nylon carpet, its electrons rub off onto your skin, and the hairs on your arm tend to become negatively charged.
The negatively charged hairs on your arm are attracted by the positively charged (electron deficient) screen.
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