
Notes:
Note that I use the letter "V" to denote voltage rather than Ë" as I usually do. This is because in general physics work, Ë" usually stands for either Ënergy" or Ëlectric field". Some electronics reference books use the letter Ë" for voltage, while others use the letter "V", or even use the two letters interchangeably.

Notes:
It may be helpful at this point to review the number of electrons constituting one coulomb of charge: 6.25 ×10^{18} electrons.
Technically, current's mathematical definition involves calculus:

Notes:
While it is easy enough for students to look up definitions for these words from any number of references, it is important that they be able to cast them into their own words. Remembering a definition is not the same as really understanding it, and if a student is unable to describe the meaning of a term using their own words then they definitely do not understand it! It is also helpful to encourage students to give reallife examples of these terms.
Notes:
This question is not as easy to answer as it may first appear. Certainly, electric current is defined as the "flow" of electrons, but how do electrons "flow" through a solid material such as copper? How does anything flow through a solid material, for that matter?
Many scientific disciplines challenge our "common sense" ideas of reality, including the seemingly solid nature of certain substances. One of the liberating aspects of scientific investigation is that it frees us from the limitations of direct sense perception. Through structured experimentation and rigorous thinking, we are able to ßee" things that might otherwise be impossible to see. We certainly cannot see electrons with our eyes, but we can detect their presence with special equipment, measure their motion by inference from other effects, and prove empirically that they do in fact exist.
In this regard, scientific method is a tool for the expansion of human ability. Your students will begin to experience the thrill of "working with the invisible" as they explore electricity and electric circuits. It is your task as an instructor to foster and encourage this sense of wonder in your students' work.
Notes:
Like all other physical quantities, there are units of measurement appropriate for specifying electrical quantities. In this sense, the "volt," ämp," or öhm" are no different from "gram," ÿard," or "bushel."
Notes:
One of the more confusing aspects of electrical theory is that both voltage and resistance are quantities relative between two points. It is meaningless to speak of the amount of voltage ät this point" in a circuit, at least without implying a reference point such as ground. The same goes for resistance: it makes no sense to speak of how much electrical resistance there is ät this point" in a circuit either.
Conversely, it makes perfect sense to speak of either voltage or resistance lying "between this point and that point," because both these quantities are relative between exactly two points.
Current, on the other hand, is the coordinated motion of electric charge through a conductor. As such, it may be measured at any single point in a circuit, like measuring the flow of water in a river at any one particular crosssectional sample.
Notes:
I usually avoid spending a lot of time on technical definitions, because undue emphasis on the definitions of words tends to reinforce rote memorization rather than true comprehension. If students must master certain definitions, though, it is best to develop that mastery in the context of application: ask the students to use their new vocabulary, not just recite it.
Notes:
This question challenges students' comprehension of voltage and current by asking them to explain the relationship between the two quantities in practical contexts. Do not allow students to simply give a ÿes" or a "no" answer to either of the stated conditions. Encourage them to think of examples illustrating a possible condition.
The term ßuperconducting" may spur some additional questions. As usual, do not simply tell students what superconductivity is, but let them research this on their own. Your more inquisitive students will probably have already researched this topic in response to the answer!
Notes:
This sheds some light on why the letter Ë" is often used to symbolize voltage in mathematical equations. Some of your students may wonder later why the letter Ï" is used to represent current. Let them research this on their own!
Notes:
This problem is another exercise in using scientific notation, and requires that students put concepts together that were learned previously.
Notes:
Though it may seem oxymoronic to refer to either "DC" or ÄC" voltage (Direct Current voltage, or Alternating Current voltage  "current voltage"?), the usage of these acronyms as such is commonplace.