Week 2: Ohm's Law

"Ohm's Law"

-Ohm's law states that the current through a conductor between two points is directly proportional to the potential difference across the two points. Introducing the constant of proportionality, the resistance, one arrives at the usual mathematical equation that describes this relationship:

where I is the current through the conductor in units of amperes, V is the potential difference measured across the conductor in units of volts, and R is the resistance of the conductor in units of ohms.

Ohm's Law triangle:

In our 2nd week, We also discussed the two types of elements that are in an Electrical Circuit. These are Passive Elements and Active Elements.

Active Elements- These elements generate energy. Examples are Batteries, generators, and operational amplifiers.

Passive Elements- These elements drop energy. They cannot generate energy because they take energy from a circuit. Examples are Resistors, Capacitors, and Inductors.

Also in our 2nd week, We also discussed the following: Open Circuits and Short Circuits.

Open Circuit- is a condition in an electric circuit in which there is no path for current between two points; examples are a broken wire and a switch in the open, or off, position.

Short Circuit-  is an electrical circuit that allows a current to travel along an unintended path, often where essentially no (or a very low) electrical impedance is encountered.

In our 2nd week, We also discussed Conductance. Conductance is

- An expression of the ease with which electric current flows through a substance. In equations, conductance is symbolized by the uppercase letter G. The standard unit of conductance is the siemens (abbreviated S), formerly known as the mho.

When a current of one ampere (1 A) passes through a component across which a voltage of one volt (1 V) exists, then the conductance of that component is 1 S. The siemens is, in fact, equivalent to one ampere per volt. If G is the conductance of a component (in siemens), I is the current through the component (in amperes), and E is the voltage across the component (in volts), then:

Reflection:

In our 2nd week of CpE 311, I learned that there is another way to identify if a component in a circuit is a passive element or an active one. In our previous lesson, Sir Jay taught us that if the current enters a negative terminal and then exits a positive terminal, then the component is an Active Element. Otherwise, if the current enters a positive terminal and exits a negative terminal, then the component is a Passive Element. Also in our previous lesson, He explained to us Ohm's  Law with the following illustration:

In this illustration, A man is pushing a table. With relation to newton's 2nd law of motion, The force that the man exerts to make the table move is the "Voltage", the movement of the table is the "Current", And the friction that resists the movement of the table is the "Resistance".

Ohm's Law

Active & Passive Elements:

Once again, Thank you for visiting my Blog. The third post will be arriving next week :D.

About the author:

Roswaldo S. Flores BSCpE-3

CpE 311

Instructor:

Engr. Jay S. Villan, MEP