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Understanding Voltage in Electric Circuits
Dive into the world of voltage and electric circuits. Explore key concepts, laws, and real-world applications. Boost your electrical engineering skills with our comprehensive guide.

Now Playing:Voltage – Example 0a
Intros
  1. What makes up a circuit?
  2. What does it mean by "series" and "parallel" configurations?
Examples
  1. Finding Voltage in Series Configuration
    Calculate the total voltage drops across the resistors in this circuit. Explain how Kirchhoff's 2nd Rule applies here.

    Introduction to Waves
    Voltage
    Jump to:NotesConceptFAQsPrerequisites
    Notes

    In this lesson, we will learn:

    • What is an electric circuit and what are the main components: battery (voltage), closed wire path (current), and devices/resistors that use up electricity (resistance)?
    • How to draw a schematic diagram using simplified symbols to represent a circuit.
    • How to tell the difference between series vs. parallel configurations for resistors in a circuit.
    • What is a battery and how does it provide voltage for an electric circuit?
    • What is voltage?
    • Kirchhoff’s 2nd Rule: Loop Rule for solving voltage questions
    • Voltage in parallel rule: the voltage used in parallel settings are EQUAL

    Notes:

    • An electric circuit is a closed loop that electric charge flows within; circuits contain 3 main components:
      • (1) a source of electrical energy (battery)
      • (2) a complete pathway for electric charges to flow through (wire), and
      • (3) one or more devices that use up electricity (electronics, resistors).
    • A schematic diagram is a simplified drawing of an electric circuit which uses universal symbols for each component of an electric circuit. A battery’s (+) positive terminal is drawn as a longer line whereas its (-) negative terminal is drawn as a shorter line.
    • The conventional current is the flow of positive charge, starting from the battery’s (+) positive terminal, travelling through the entire circuit, and ending at the (-) negative terminal.
    • An electric circuit’s attached electronic devices (lightbulbs or resistors) can be connected in either series or parallel configurations.
      • Series: resistors are connected in series if they are in a single and continuous path
      • Parallel: resistors are connected in parallel if they are in multiple, branching paths
    • A battery provides voltage to an electric circuit; it drives the electricity throughout the circuit.
      • A battery converts chemical energy into electrical energy; the reduction-oxidation reaction that occurs within the battery generates excess free energy which is put into the circuit as electrical energy.
    • Voltage is a type of electrical potential difference. The voltage of a battery represents how much energy it can provide the circuit; voltage can also represent how much energy is lost/used across resistors/devices (“voltage drop”).
    • The unit for voltage is Volts (V) (which is equivalent to Joule/Coulomb or energy per charge). It is a scalar quantity.
    • Kirchhoff’s 2nd Rule, also known as the Loop Rule, states that the sum of charges in electric potential (voltage) around the circuit (closed path) will be equal to zero.
      • In other words, all the voltage stored in the battery will be used up by the devices (resistors) in the circuit; the magnitude of battery voltage is equal to the sum of all voltage drops across resistors in the circuit.
    • Voltage in parallel configurations have a special rule: the voltage used in parallel settings are EQUAL (each parallel branch will have the same amount of voltage drop).
    • We will use the stair case analogy for voltage (going down stairs in a building).
      • Starting with the battery voltage (at the positive terminal) as the top floor, and going down a number of floors at each resistor (voltage drop), until you get to floor zero (end at the negative terminal)
    Concept

    Introduction to Voltage in Electric Circuits

    Voltage is a fundamental concept in electrical engineering, playing a crucial role in understanding how electric circuits function. Our introduction video provides a comprehensive overview of voltage, making it an essential starting point for anyone delving into the world of electronics. Voltage, often described as electrical pressure, is the force that drives electric current through a circuit. It's measured in volts and represents the potential difference between two points in an electrical system. This concept is vital for designing and analyzing circuits, from simple household appliances to complex industrial systems. The video explores how voltage sources, such as batteries or power supplies, create this potential difference, and how it affects the flow of electrons. By grasping the basics of voltage, students and enthusiasts can build a solid foundation for more advanced electrical concepts, making it an indispensable topic in any electrical engineering curriculum.

    FAQs

    1. What is voltage and how is it measured?

      Voltage is the electric potential difference between two points in an electrical circuit. It's measured in volts (V) using a voltmeter or multimeter. Voltage represents the force that drives electric current through a circuit and is often described as electrical pressure.

    2. How does voltage behave in series and parallel circuits?

      In series circuits, voltage is divided across components, with the total voltage equal to the sum of individual voltage drops. In parallel circuits, voltage remains constant across all branches, with each component experiencing the same voltage as the source.

    3. What is Kirchhoff's Voltage Law?

      Kirchhoff's Voltage Law (KVL) states that the sum of all voltage changes around any closed loop in an electrical circuit must equal zero. This law is based on the principle of conservation of energy and is crucial for analyzing complex circuits.

    4. How does voltage relate to power in electrical systems?

      Power in electrical systems is calculated by multiplying voltage by current (P = V * I). Higher voltage can deliver more power for a given current, which is why high-voltage transmission lines are used for efficient long-distance power distribution.

    5. What are some common voltage levels in everyday applications?

      Common voltage levels include 1.5V for AA batteries, 3.7V for smartphone batteries, 5V for USB charging, 12V for car electrical systems, and 120V or 230V for household mains power, depending on the country. Understanding these levels is important for safely using and designing electrical devices.

    Prerequisites

    Understanding the concept of voltage is crucial in the field of electrical engineering and physics. However, to fully grasp this fundamental concept, it's essential to have a solid foundation in its prerequisite topics. One of the most important prerequisites for understanding voltage is electric potential and electric potential energy.

    Electric potential and electric potential energy form the basis for comprehending voltage. These concepts are intrinsically linked to the idea of electric potential difference, which is essentially what voltage represents. By delving into these prerequisite topics, students can develop a more comprehensive understanding of how electrical energy is stored and transferred within a system.

    The relationship between electric potential and voltage is particularly significant. Electric potential, often measured in volts, represents the amount of electric potential energy per unit charge at a given point in an electric field. This directly relates to voltage, which is the difference in electric potential between two points in an electrical circuit.

    Understanding electric potential and electric potential energy helps students grasp the concept of work done by electric forces. This knowledge is crucial when studying voltage, as it explains how electrical energy is converted into other forms of energy in various applications.

    Moreover, the prerequisite topic of electric potential difference is essential for comprehending voltage in practical scenarios. It helps explain why electrical current flows from areas of high potential to low potential, which is the fundamental principle behind the operation of electrical circuits and devices.

    By mastering these prerequisite concepts, students can more easily understand complex topics related to voltage, such as Ohm's law, electrical resistance, and power in electrical systems. The knowledge of electric potential and electric potential energy also provides a solid foundation for advanced studies in electromagnetism and electrical engineering.

    In conclusion, a thorough understanding of electric potential and electric potential energy is vital for students aiming to master the concept of voltage. These prerequisite topics not only provide the necessary background knowledge but also help in developing a intuitive grasp of electrical phenomena. By investing time in studying these foundational concepts, students can significantly enhance their understanding of voltage and its applications in various fields of science and technology.