My question was was that though you don't have any charge on the inner surface of a metallic cavity but still there's a potential. Can't that potential electrocute someone?
Takes a potential difference to shock you.Can't that potential electrocute someone?
Thank you sir. It really helpednIt takes about 1 mA across the heart to cause cardiac arrest. However the skin has a resistance of several hundred kΩ when dry (much lower when wet) and current through the body often skips the heart. (Other organs can be affected, and sometimes destroyed at higher current levels as well.) So any amount of current is fine at low voltage levels. Your skin protects you. (Unless your skin is broken. Metallic medical needles used to be a common danger.)
Most high voltage demonstration equipment doesn't exceed the 1 mA level, but often experimental equipment does. Use with caution.