We cover electric current first and we answer:

• What is electrical current and how do we define electric current?
• What particle is responsible for electric current?
• What is electric charge, how do we designate it and what unit do we use for electric charge?
• Which particles are “charged” and what is the sign of their charge?
• Does any charge that moves really make an electric current? Which particles are “free” to move?
• What types of materials are there and do they all conduct electricity?
• Which materials are particularly suitable for electronics?
• How do we achieve directed movement of charge in conductors?
• How do we indicate direction of electric current?
• What is “reference” direction and how does it relate to actual flow of current?
• How do we designate quantities that are constant in time vs those that change in time?
• What formula connects electric charge and electric current?
• How do we calculate electric current if flow of charge changes in time?
• What is the unit of electric current and how do we designate electric current in electrical circuits?
• Why do we “dope” semi-conductors with impurities?
• What are the most frequently used materials in electronics?

Next, we cover electric voltage as the second key electrical quantity. We answer:

• What is electrical voltage and what is its definition?
• What is the difference between electric “potential” and electric “voltage”?
• Why do we always need to have two points when we talk about electric voltage?
• What is the purpose of “ground” with respect to electric voltage and what is electric potential of ground?
• What does it mean: points are connected together?
• What language do we use to express electric voltage of an element?
• How do we designate electric voltage as a quantity and on electrical schematics?
• What is reference polarity or assumed polarity versus actual polarity of a voltage?
• What is the unit for electric voltage?
• Which law is used to relate voltage and current of an element?
• What is electrical resistance, how do we designate it and what unit do we use for the resistance?
• When is voltage positive and when does it have negative value?
• Do we have the same rules for positive vs negative value of a current that flows through an element?
• Are actual directions and/or polarities really important?

Next quantity we analyze is electric power and we consider the following aspects of it:

• How do we call electric power that changes in time?
• How do we calculate electric power and what quantities do we use in formula for electric power?
• What is the expression for power in Direct Current (DC) circuits?
• What letter is used for power in DC circuits and what is the unit of electric power?
• What are the alternative ways of calculating electric power in resistive electrical circuits?
• What is the alternative way of defining electric power with respect to electric energy?

The last quantity we cover is electric energy. We answer the following:

• How do we obtain electric energy for an element if we know how its power changes in time?
• What is the simplified way of calculating energy in DC circuits?
• What unit do we use for electric energy and why do we use “different” unit than what we use in physics?
• How do we convert energy units expressed with different time bases?
• What prefix is most frequently used in expressing electric energy of an element?