I am in the beginning part of the Electronics Associate Degree. I know that I will study calculus later on in the course. Just what is calculus, anyway? Q. The soldering lessons say to use only rosin-core solder in electronics work, and not to use acid-core solder. What is wrong with using acid-core solder? I am in Course 1B. What kind of calculator should I have for this course? I would like to operate 120V appliances off a 12V battery. I have heard that there are devices that let you do this. What are they and how do they work? In the oscillator lab lesson we build some LC oscillators and then pick up their signals on an AM radio. Why do the oscillators give off radio signals? Learn how computer chips being made today have millions of transistors on them. I am studying Lesson 2405 on amplifiers. In it there is a description of the harmonics of a signal. I don’t understand this. Q. I have been studying filter circuits, and I think I understand them pretty well. What are filter circuits used for, anyway? Q. When you are working with electricity, is it safer to be grounded? I have seen LCDs in things like calculators and watches. How do these work and why are they used instead of something like LED displays?