A person can be killed if a current as small as 50 mA passes near the heart. An electrician is working on a humid day with hands damp from perspiration. Suppose his resistance from one hand to the other is 1 kOhm and he is touching two wires, one with each hand.
a.) What potential difference between the two wires would cause a 50 mA current from one hand to the other?
b.) An electrician working on a live current keeps one hand behind his back. Why?