While it's true the lethal amount of current across the heart is very low, it takes a whole lot of voltage to allow that amount of current to flow through your heart.
Not necessarily. Depends on where the voltage is applied, sweaty hands holding a metal wrench, in the bathtub using a telephone, patients connected to medical equipment, standing in the rain working on a "low voltage" piece of electrical equipment you though was turned off, accidentally cutting your finger on an electrical connector, etc.
Also joules is a measure of energy per time, the longer the time the more joules that flow, shorter time, less joules.
Joules is a measure of energy. Power is energy per unit time.
DC reacts to resistance more than AC
No. Period. End of story. See Ohm's Law.
it takes a fair bit more DC volts to generate lethal current across the heart than it does AC. 24VAC will cause muscle contractions and some pretty bad feelings. It takes around 50VDC to feel the current flowing through your body.
Current flows through things. Voltage is across things. AC current is more efficient than DC at causing ventricular fibrillation. The other potentially lethal effects of electrical current aren't necessarily more potent with AC than with DC. Long term low levels of DC current may have some effects that AC doesn't due to the effects of electrolysis, according to some posts in this thread.
You're more likely to die from higher voltages than low because they will travel farther through your body.
No. Current always flows all the way from one contact point through your body to the other contact point on your body. For instance from your hand touching a live circuit to your feet touching the ground. Higher voltage simply increases the amount of the current. (Except where the voltage is high enough to arc through the air and electrocute you from a conductor you're not touching.)
The actual chances of being electrocuted from normal circumstances of the average person is very low. It's hard to generate a short across your heart with current electrical codes. Sure you could burn yourself very badly, or cause muscle damage and soft tissue damage, but death is unlikely.
Yes, chances of electrocution are low. 500 or so per year in the use. Thank goodness.
No, it's not hard to get electrocuted. Work on a live house wiring circuit, and it's easy to electrocute yourself. The circuit breaker will not usually save you unless it's a GFCI breaker. Work on a consumer electronic device like a DVD player and it's easy to electrocute yourself. Once you remove the cover, there may well be exposed 115VAC terminals.
It may be hard to electrocute yourself if you use all your devices the way they were designed to be used. Many CPF members are electrical tinkerers. Many of them aren't engineers or electricians or any other kind of trained electrical professional. Many of us do extreme electrical things with normally low-voltage equipment. Many of us will open things up and probe voltages with the power on. Want to bet you couldn't electrocute yourself if you open up a 35W HID spotlight even though the battery is only 12V?
We should not get too callous about the dangers of electricity.
I'm an electrical engineer. I worked for years on electrical safety for consumer electronic equipment, factory equipment, international, US, and internal company safety standards, including the US National Electric Code. Not only do I understand the rules, I understand the underlying risks involved.
When I give advice, I do go overboard on pointing out even the unlikely scenarios because I know someone will go out and try it.
