Basic laws of Electronics

This post is about refreshing some of the basics concepts in electronics which is being used by all electronic designers in daily work,

Ohm’s Law:

The amount of current through a conductor is directly proportional to the voltage applied across it for any given temperature.

Polarity of Voltage drop:

• Polarity of voltage drop is determined by the direction of flow of electrons.
• Negative (-ve) for electron entering
• Positive (+ve) for electron exiting

Kirchoff’s Voltage Law:

• Algebraic some of all voltages in a loop is equal to zero.

Kirchoff’s Current Law:

•  Algebraic some of all currents entering and exiting a node is equal to zero.

 Voltage Divider Rule:

• The source voltage (V) is divided across the resistors and the voltage drop across a particular resistor (Rx) is given as below,

 Vx = V*(Rx/Rt)

Rt = Total Resistance

Vx = Voltage across the Resistor Rx

Current Divider Rule:

• The current (I) is divided among branches in a parallel circuit.The current in a particular branch is calculated as below,

In the reference Fig. current through R1 is calculated.