- #1
ice109
- 1,714
- 6
why do we get zapped by door knobs? they're not grounded? well maybe they are when the door is closed...
mgb_phys said:What's so special about the earth?
The reason you get a shock to Earth is that it is large enough that the small amount of charge flowing from you doesn't change it's potential (voltage) so the charge can keep flowing.
Simimairly with a door knob, it's a relatively large isolated metal object so can contain a large amount of charge - so when you touch it there is a large potential difference which doesn't decrease, allowing all the charge to keep flowing from you.
It's a bit like touching a bath of hot water rather than a tiny spark. The spark is hotter but soon cools, the water can keep putting heat into you for longer.
When we touch a door knob, we are completing an electrical circuit between the doorknob and our body. This causes a buildup of static electricity, which results in a small electric shock.
Some people tend to build up more static electricity than others due to differences in body chemistry, clothing materials, and environmental factors such as humidity and carpeting. Additionally, some people may have a higher sensitivity to electric shocks.
In most cases, the shock from a door knob is not dangerous. However, it can be more intense for individuals with certain medical conditions, such as a heart condition or pacemaker. Additionally, a shock from a metal doorknob could be dangerous if it causes a person to lose their balance and fall.
To reduce the likelihood of getting zapped by door knobs, we can try to minimize static electricity buildup by wearing natural materials, using lotion or anti-static spray on our hands, and keeping the humidity level in our home at a moderate level. We can also try to discharge any built-up static electricity before touching a doorknob by touching a grounded object, such as a metal appliance or water faucet, first.
While getting zapped by door knobs may not seem like a pleasant experience, it can actually have some benefits. It can help to discharge any built-up static electricity, preventing potential damage to electronic devices or discomfort from static cling. Additionally, it can serve as a reminder to ground ourselves and discharge any excess static electricity regularly, which can improve our overall safety and well-being.