1. The problem statement, all variables and given/known data Ok, this is not actually a homework, but I still need help ... would somebody be so kind and explain me how to solve these 4 questions? Thanks! I already have answers on them (all answers are true/false type ... but I need to know WHY). Thanks! [Broken] [Broken] [Broken] [Broken][/quote] 2. Relevant equations 3. The attempt at a solution 1) LED light: When both inputs in AND gate are true (positive), current will flow through them to the LED. But since second AND gate input is hardwired to negative, how can switch S1 turn ON/OFF the LED? I really do not understand. 2) Not a clue on this one. 3) Same as above, I do not a have a clue. It there a similar problem with a complete solution so I can learn by "reverse engineering"? 4) a) First number in equation tells the effective voltage? b) Looks like the answer is first number * 2/pi, but can somebody explain me why?