Electricity

• What is current?


  Current (I) is the flow of charge (electrons) through a conductor, typically measured in amperes (A).
• What does a resistor look like in a circuit?


  A resistor is represented by the symbol ().
• What does a capacitor look like in a circuit?


  A capacitor is represented by the symbol ().
• What does an inductor look like in a circuit?


  An inductor is represented by the symbol ().
• What does a switch look like in a circuit?


  A switch is represented by the symbol (S).
• What does a battery look like in a circuit?


  A battery is represented by the symbol (B).
• What type of circuit is shown below?

  A circuit where multiple components are connected one after the other, so that the current flows through each component in sequence. Series Circuit.
• What type of circuit is shown below?

  A circuit where multiple components are connected between the same two points, so that they share the same voltage and current. Parallel Circuit.
• Resistance


  Opposition to the flow of electric current
• v=IR


  Formula to calculate electric current: voltage = resistance x current
• Causes of resistance


  Materials, length, temperature, impurities, and surface roughness
• Temperature and resistance


  Most materials increase resistance with temperature, except semiconductors which decrease resistance
• Linear I-V Characteristics of a Resistor


  Resistors exhibit a straight-line relationship between voltage and current; resistance remains constant as voltage increases
• Ohmic Behavior of a Resistor


  Resistors exhibit linear, predictable, and constant resistance relationship between voltage and current
• Voltage-Current Ratio


  Constant ratio of voltage to current, equal to the resistance (R)
• Resistance Remains Constant


  Resistance of a resistor remains constant as voltage increases
• Current Varies with Voltage


  Current through a resistor varies linearly with voltage applied
• High Voltage Effects on Resistors


  Breakdown voltage, ionization, and arcing can occur at very high voltages
• Low Voltage Effects on Resistors


  Leakage current, surface effects, and bulk effects can occur at very low voltages
• Voltage Divider


  A circuit that divides a voltage into two or more parts, with output voltage proportional to the ratio of the resistors
• Voltage Ratio


  The ratio of the voltage across each resistor is equal to the ratio of their resistances
• Current Divider Formula


  Current flowing through each branch is proportional to the resistance of the corresponding branch
• Current Ratio


  Ratio of current in each branch is equal to the ratio of the resistances of the corresponding branches
• Series Circuit


  A circuit where components are connected one after the other, with current flowing through each component in sequence
• Current Flow in Series Circuit


  Current flows through each component in the same direction, from the positive terminal of the power source to the negative terminal
• Total Resistance of Series Circuit


  The total resistance is the sum of the resistances of each component
• Advantages of Series Circuit


  Efficient power transmission, easy to analyze, improved reliability, simplified circuit protection, and cost-effective
• Parallel Circuit


  A circuit where components are connected between the same two points, but each component has its own separate path for current to flow
• Current Flow in Parallel Circuit


  Current flows through each component simultaneously, with each component having its own separate path
• Total Resistance of Parallel Circuit


  The total resistance is less than the resistance of any single component, with current able to flow around faulty components
• Parallel Circuits in Power Distribution


  Used to distribute power to multiple devices or lights in a building
• Parallel Circuits in Audio Systems


  Used to combine multiple signals or speakers, allowing for a louder or more balanced output
• Parallel Circuits in Electric Vehicles


  Used to allow multiple electric motors to operate simultaneously, providing improved torque and efficiency
• Parallel Circuits and Fault Tolerance


  If one component fails or is removed, the other components continue to operate, ensuring the overall system remains functional
• Parallel Circuits and Current Handling


  Can handle higher currents than series circuits, making them suitable for applications that require high current handling
• Parallel Circuits and Voltage Regulation


  Provide better voltage regulation, with smaller voltage drop across each component
• Series Circuit


  A circuit where components are connected in a chain, one after the other
• Parallel Circuit


  A circuit where components are connected between the same two points
• Series Circuit Total Resistance


  The total resistance is the sum of individual resistances
• Parallel Circuit Total Resistance


  The total resistance is less than the resistance of any single component