Combination of Resistors
Enroll to start learning
You’ve not yet enrolled in this course. Please enroll for free to listen to audio lessons, classroom podcasts and take practice test.
Interactive Audio Lesson
Listen to a student-teacher conversation explaining the topic in a relatable way.
Introduction to Series Combination
🔒 Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Today we're going to learn about the series combination of resistors. Can anyone tell me what happens when resistors are connected in series?
I think the total resistance increases.
Exactly! The total resistance is the sum of the individual resistances: R_eq = R_1 + R_2 + R_3, and the same current flows through each resistor. This is also known as 'one path for the current.'
What about the voltage across each resistor?
Good question! The voltage divides across the resistors in series. The total voltage is equal to the sum of the voltages across each resistor.
So, if one resistor fails in a series circuit, does the whole circuit stop?
Yes, that's correct! In a series connection, if one resistor breaks, it will open the entire circuit.
Let's summarize what we've learned in this session about series combinations: we add resistances to find the total, the same current flows, and voltage divides.
Introduction to Parallel Combination
🔒 Unlock Audio Lesson
Sign up and enroll to listen to this audio lesson
Now that we've covered series combinations, let's move on to parallel combinations. Who can tell me how resistors behave when connected in parallel?
I believe the voltage stays the same across each resistor?
That's right! In a parallel circuit, the voltage across each branch is equal to the total voltage. Now, how do we calculate the total resistance?
Isn't it the reciprocal of the sum of the reciprocals of each resistance?
"Exactly! It can be expressed as \(
Introduction & Overview
Read summaries of the section's main ideas at different levels of detail.
Quick Overview
Standard
In this section, we learn two primary methods for combining resistors: in series, where the total resistance is the sum of individual resistances and the current remains constant, and in parallel, where the total resistance can be calculated from the reciprocal of the sum of the reciprocals of individual resistances and voltage remains constant across all components.
Detailed
Detailed Summary
In the combination of resistors, we can configure resistors in two main arrangements: series and parallel. In a series combination, the total resistance (
R_eq) is simply the sum of the individual resistances (R_1 + R_2 + R_3 + ...). This configuration means that the same current flows through each resistor but the voltage across each one varies according to its resistance. Conversely, in a parallel combination, the total resistance can be calculated using the formula:
\[ \frac{1}{R_{eq}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + ... \]
In this case, the voltage across each branch remains the same, while the total current divides among the various paths. Understanding these combinations is crucial for analyzing complex circuits and is fundamental for solving real-world electrical problems.
Audio Book
Dive deep into the subject with an immersive audiobook experience.
Series Combination of Resistors
Chapter 1 of 2
🔒 Unlock Audio Chapter
Sign up and enroll to access the full audio experience
Chapter Content
Series Combination:
\[ R_{eq} = R_1 + R_2 + R_3 + \ldots \]
- Same current flows.
- Voltage divides.
Detailed Explanation
In a series combination of resistors, the total or equivalent resistance (R_eq) is the sum of all individual resistances (R_1, R_2, R_3, ...). This means that the current flowing through each resistor in the series is the same. However, the voltage across each resistor can vary depending on its resistance. The total voltage supplied across the series is divided among the resistors.
Examples & Analogies
Think of water flowing through a series of narrow pipes connected one after another. The same amount of water (current) must flow through each section (resistor), but if some sections are narrower (higher resistance), the water pressure (voltage) will be lower in those areas.
Parallel Combination of Resistors
Chapter 2 of 2
🔒 Unlock Audio Chapter
Sign up and enroll to access the full audio experience
Chapter Content
Parallel Combination:
\[ \frac{1}{R_{eq}} = \frac{1}{R_1} + \frac{1}{R_2} + \frac{1}{R_3} + \ldots \]
- Voltage remains same.
- Current divides.
Detailed Explanation
In a parallel combination, the total or equivalent resistance (R_eq) is found using the reciprocal formula. In contrast to series, the voltage across each resistor in a parallel circuit is the same as the source voltage. However, the total current flowing from the source is divided among all the paths (resistors) inversely to their resistances. So, if one path has less resistance, it will carry more current.
Examples & Analogies
Consider a multi-lane highway where cars (current) can take different lanes (paths/resistors) to reach the same destination (power source). Even if the speed limit (voltage) is the same in all lanes, cars will adjust their speeds based on the traffic on each lane—cars in the less congested lanes will go faster (more current).
Key Concepts
-
Series Combination: An arrangement where resistors are connected end-to-end, leading to a total resistance that is the sum of individual resistances.
-
Parallel Combination: An arrangement where resistors are connected across the same two points, maintaining the same voltage across all branches but allowing the total current to divide.
-
Equivalent Resistance: The total resistance presented by the circuit that can replace the entire network of resistors.
Examples & Applications
In a series circuit with resistors of 2Ω, 3Ω, and 5Ω, the equivalent resistance is 10Ω.
In a parallel circuit with resistors of 4Ω and 6Ω, the equivalent resistance is 2.4Ω.
Memory Aids
Interactive tools to help you remember key concepts
Rhymes
In series, add along the way, voltage splits, come what may.
Stories
Imagine a line of cars on a one-lane road (series), each car must wait its turn. Now picture a freeway with many side streets (parallel) where cars can take different paths all at once!
Memory Tools
S for Series means Sum (R_total = R_1 + R_2). P for Parallel means Parts (1/R_eq = 1/R_1 + 1/R_2).
Acronyms
S for Same current in Series, P for Parallel where current splits.
Flash Cards
Glossary
- Series Combination
A way of connecting resistors in which the end of one resistor is connected to the beginning of the next.
- Parallel Combination
A way of connecting resistors where all the resistors' ends are connected together, providing multiple paths for current flow.
- Equivalent Resistance (R_eq)
The total resistance of a circuit in a specific configuration such as series or parallel.
Reference links
Supplementary resources to enhance your learning experience.