Wow! Technically, this "should" do nothing but trip the circuit breaker. But "should" (theory) and "would" (real-world) are not always in agreement. I can see how serious burns, or perhaps sparks flying into nearby inquisitive eyes could happen.
Or she's sufficiently grounded, and the penny touches only the hot terminal of the plug...Murphy's Law.
I received a pretty good shock as a child and no circuit breakers were tripped. I certainly would not trust one to save a life in this situation.
Without more information, you getting a shock really does not suggest anything. The penny across the two terminals would surely trip a properly functioning breaker because the penny, being made out of copper, an excellent conductor, would have caused a direct short to near 0 ohms. And Ohm's Law dictates that when resistance drops, current goes up. So the circuit breaker would have seen the excess current and tripped immediately. Human bodies conduct, but in reality are poor conductors of electricity. So when you came across that current, resistance would have dropped but not to anything close to 0 ohms. So the breaker would not have tripped, at least not immediately - especially since your body likely jerked away and broke contact. Regardless, no. You should never "trust" any circuit breaker would save your life. One can only hope they do their job correctly. If "Man" can ever create perfection 100% of the time, then and maybe only then can you trust the breaker. I probably wouldn't though. And for the record, I feel your pain. Long ago, I was on my hands and knees scrubbing the laundry room floor and came up against the metal bottom of the freezer. I was thrown across the room - probably more from my body convulsing rather than the shock itself. In any case, I refused to go back in there until my dad ensured the outlet and freezer were properly grounded. That was probably the incentive for me learning electronics and becoming an electronic technician.
I should think so LOL. It takes >15 Amps to trip a typical householed breaker, and only .01 Amps through the heart or 0.1 Amps through the body to kill a human. Anyway, no more from me. Veering OT.
