FUNDA - PRELIM

1752 (Benjamin Franklin)

Demonstrated the nature of electricity using a kite, string, and key.

1776 (James Watt)

Commercialized the steam engine; his name is attributed to the SI unit of power

1786 (Luigi Galvani)

Observed bioelectricity causing muscle twitching in frogs

1792 (Alessandro Volta)

Invented the chemical battery; named as the unit of electric potential (volt)

1827 (André-Marie Ampère)

Formulated the foundations of electrodynamics; named as the unit of current

1827 (Georg Simon Ohm)

Formulated the relationship between voltage, current, and resistance (Ohm's Law)

1882 (Thomas Edison)

Deployed the first commercial direct current (DC) generators to illuminate New York City

1885 (George Westinghouse & Nikola Tesla)

Developed and commercialized alternating current (AC) generators and motors

Work or Energy (W or E)

Measured in Joule (J); the capacity to do work

Electric Current (I)

Measured in Ampere (A) (1 A = 1 C/s)

Power (P)

Measured in Watt (W); the time rate of expending or absorbing energy

Electric Charge (Q)

Measured in Coulomb (C).

Voltage (V)

Measured in Volt (V) (1 V = 1 J/C)

Prefix & Multiplier

tera: 12

giga: 9

mega: 6

kilo: 3

deka: 0

milli: -3

micro: -6

nano: -9

pico: -12

Charge of an electron (e)

-1.602 x 10^-19 C

Law of Conservation of Charge

Charge cannot be created or destroyed; it is only transferred

Law of Conservation of Power

Total power delivered to a circuit equals total power absorbed

Power Formula

Voltage Formula

Charge Formula

Law of Conservation of Power Formula

Active Elements

Capable of generating electrical energy (e.g., DC/AC voltage and current sources, transistors, integrated circuits

Passive Elements

Incapable of generating energy

Resistor

Regulates current flow and limits voltage by creating voltage drops

Diode

Restricts electric current to a single direction

Capacitor

Stores and releases electric energy in an electrostatic field

Inductor (Coil)

Creates an electromagnetic field to impede alternating current (AC) while passing direct current (DC)

Transformer

Transfers electrical energy across circuits via electromagnetic induction

Active Elements examples

DC/AC voltage and current sources, transistors, integrated circuits

Passive Elements Examples

Resistor

Diode

Capacitor

Inductor (Coil)

Transformer

Conductor

Low-resistance material that readily permits current flow (e.g., Copper, Aluminum, Brass, Silver, Gold, Platinum, Carbon)

Insulator

High-resistance material that blocks current flow

Conductor Examples

Copper

Aluminum

Brass

Silver

Gold

Platinum

Carbon

Insulator e.g.

Plastic

Rubber

Glass

Porcelain

Air

Paper

Mica

Ceramics

Mnemonic

Bad beer rots out your guts but vodka goes well

Ohm’s Law

Current (I) is directly proportional to voltage (V) and inversely proportional to resistance (R) at a constant temperature

Ohm’s Law F

Branch

Represents a single two-terminal circuit element (e.g., a resistor, diode, or source)

Node

A point of connection where two or more branches meet

Loop

Any closed conducting path through a circuit

Kirchhoff's Current Law (KCL)

Based on the Conservation of Charge; The algebraic sum of currents entering and exiting a node is zero

KCL F

Kirchhoff's Voltage Law (KVL)

Based on the Conservation of Energy; The algebraic sum of all voltages around any closed loop is zero

KVL F

Voltage Drop in Sign Convention (Clockwise Loop)

Entering a positive (+) terminal and exiting negative (-); written as +V

Voltage Rise in Sign Convention (Clockwise Loop)

Entering a negative (-) terminal and exiting positive (+); written as -V

Series Equivalent Resistance

Voltage Division Rule (VDR - Series Circuits)

Current Division Rule for two parallel resistors (CDR - Parallel Circuits):

Current Division Rule for N parallel resistors (CDR - Parallel Circuits):

Delta to Wye

Wye to Delta