Ohm’s law  Electric Circuits
Ohm’s law
Lessons
Notes:
In this lesson, we will learn:
 A review on the electric circuit and the main components: battery (voltage), closed wire path (current), and devices/resistors that use up electricity (resistance).
 Also, a review on the main rules/methods we used to solve for each concept individually (voltage and Kirchhoff’s Loop Rule; current and Kirchhoff’s Junction Rule; resistance summation formulas)
 What is the relationship between voltage, current, and resistance?
 How to solve circuit problems for voltage, current, and resistance using Ohm’s Law which states that:
 $V=IR$
 And also, how to rearrange Ohm’s Law: $V=IR$; $I= \frac{V} {R}$; $R= \frac{V} {I}$
Notes:
 Recall that: a circuit is a closed loop that charge flows within; the three main components of a circuit are voltage (provided by a battery source), current (the rate of flow of charge within the circuit wires), and resistance (a property of the electronic devices using up energy).
 Voltage is measured in the unit volts (V) which is equal to Joules/Coulomb
 Current is measured in the unit ampere (A) which is equal to Coulombs/Second
 Resistance is measured in the unit ohm ($\Omega$) which is equal to Volts/Ampere
 Ohm’s Law states that the voltage is equal to the current multiplied by resistance:
 $V=IR$
 For metals, resistance is constant and independent of voltage
 Voltage is directly proportional to current ($V \propto I$)
 The Ohm’s Law equation can be rearranged to solve for any of the tree main concepts (voltage, current, resistance).
 $V=IR$; $I= \frac{V} {R}$; $R= \frac{V} {I}$
 The current coming out of a battery is dependent on the resistance of the circuit its connected to
 Solving questions using Ohm’s Law requires a strong understanding of solving for the three main concepts individually
 Voltage: Kirchhoff’s 2^{nd} Rule: Loop Rule (sum of all voltages around the loop equal zero); all parallel branches are equal to the same voltage drop
 Resistance: total equivalent resistance in series ( $R_{eq(series)} = \sum_{k=1}^{n} R_{k}$ ) and in parallel ($R_{eq(parallel)} =\frac{1} { \sum_{k=1}^{n} \frac{1}{R_{k}} }$ )

Intro Lesson
Introduction to Ohm's Law:

1.
Solving for Current with a Single Resistor in Series

2.
Solving for Current and Voltage with Multiple Resistors in Series

3.
Solving for Current, Resistance, and Voltage for Circuits with BOTH Series & Parallel Configurations