Electrical Energy And Power - Ohmic conductors

  • Introduction to electrical energy and power
  • Definition of ohmic conductors
  • Relationship between current, voltage, and resistance in ohmic conductors
  • Ohm’s Law: V = IR
  • Power in ohmic conductors: P = IV
  • Calculation of electrical energy consumed: E = Pt
  • Examples of ohmic conductors
  • Applications of ohmic conductors in daily life
  • Safety precautions while dealing with ohmic conductors
  • Practice problems to understand the concepts better
  1. Examples of Ohmic Conductors:
  • Copper wires
  • Aluminum wires
  • Carbon resistors
  • Incandescent light bulbs
  • Electric heaters
  1. Applications of Ohmic Conductors:
  • Electrical wiring in buildings
  • Circuit boards in electronic devices
  • Heating elements in appliances
  • Resistors in electronic circuits
  • Filaments in incandescent light bulbs
  1. Safety Precautions while Dealing with Ohmic Conductors:
  • Always switch off the power before handling electrical connections.
  • Use proper insulation to avoid electric shocks.
  • Avoid overloading circuits to prevent overheating.
  • Ensure proper grounding to prevent excessive voltage.
  • Regularly check for damaged wires or connections to avoid short circuits.
  1. Practice Problems:
  1. Calculate the current flowing through a 10-ohm resistor connected to a 20V power supply.
  1. A 60W light bulb operates at a voltage of 120V. Calculate the resistance of the bulb.
  1. A heater draws a current of 4A when connected to a 240V power supply. Find the power consumed by the heater.
  1. A circuit has a current of 2A flowing through a 5-ohm resistor. Calculate the voltage across the resistor.
  1. Solution to Practice Problem 1: Given: R = 10 ohms, V = 20V Using Ohm’s Law: V = IR

20 = I * 10 I = 20/10 I = 2A Therefore, the current flowing through the resistor is 2A.

  1. Solution to Practice Problem 2: Given: P = 60W, V = 120V Using the power formula: P = IV

60 = I * 120 I = 60/120 I = 0.5A Using Ohm’s Law: V = IR

120 = 0.5 * R R = 120/0.5 R = 240 ohms Therefore, the resistance of the bulb is 240 ohms.

  1. Solution to Practice Problem 3: Given: I = 4A, V = 240V Using the power formula: P = IV P = 4 * 240 P = 960W Therefore, the power consumed by the heater is 960W.
  1. Solution to Practice Problem 4: Given: I = 2A, R = 5 ohms Using Ohm’s Law: V = IR V = 2 * 5 V = 10V Therefore, the voltage across the resistor is 10V.
  1. Summary:
  • Ohmic conductors demonstrate a linear relationship between current, voltage, and resistance.
  • Ohm’s Law (V = IR) is used to determine the relationship between these variables.
  • Power in ohmic conductors can be calculated using the formula P = IV.
  • Electrical energy consumed is given by the equation E = Pt.
  • Ohmic conductors find applications in electrical wiring, circuit boards, and heating elements.
  • Safety precautions must be taken while handling ohmic conductors to prevent accidents.
  1. Conclusion: Ohmic conductors play an essential role in electrical circuits and power consumption. Understanding the concepts of current, voltage, resistance, power, and energy is crucial in analyzing and designing electrical systems. By following safety precautions, we can ensure the efficient and safe use of ohmic conductors in various applications.
  1. Characteristics of Ohmic Conductors:
  • Ohmic conductors have a linear relationship between current and voltage.
  • The resistance remains constant irrespective of the current flowing through it.
  • The temperature of the conductor does not significantly affect its resistance.
  • Ohmic conductors obey Ohm’s Law, which states that the current through a conductor is directly proportional to the voltage across it, given a constant resistance.
  1. Non-Ohmic Conductors:
  • Some materials, such as diodes and transistors, do not follow Ohm’s Law.
  • These materials have a non-linear relationship between current and voltage.
  • The resistance in non-ohmic conductors can vary with changes in current or voltage.
  • Examples of non-ohmic conductors include semiconductors and gas discharge tubes.
  1. Calculation of Resistance Using Ohm’s Law:
  • Ohm’s Law can be rearranged to calculate resistance.
  • The resistance (R) of an ohmic conductor can be calculated as R = V/I.
  • The unit of resistance is ohms (Ω).
  • Resistance determines how easily current can flow through a conductor.
  1. Calculation of Voltage Using Ohm’s Law:
  • Ohm’s Law can also be rearranged to calculate voltage.
  • The voltage (V) across an ohmic conductor can be calculated as V=IR.
  • This formula is useful when the current and resistance are known.
  • Voltage represents the electric potential difference across a conductor.
  1. Calculation of Current Using Ohm’s Law:
  • Ohm’s Law can be rearranged to calculate current.
  • The current (I) flowing through an ohmic conductor can be calculated as I = V/R.
  • This formula is especially helpful when voltage and resistance are given.
  • Current represents the flow of electric charge through a conductor.
  1. Power Calculation in Ohmic Conductors:
  • Power (P) in ohmic conductors can be calculated using the formula P = IV.
  • Power represents the rate at which electrical energy is consumed.
  • The unit of power is watt (W), which is equivalent to joules per second.
  • Power is commonly measured to determine the performance of electrical devices.
  1. Calculation of Electrical Energy:
  • Electrical energy can be calculated using the formula E = Pt.
  • Here, E represents the energy consumed, P is the power, and t is the time.
  • The unit of electrical energy is the watt-second (Ws) or joule (J).
  • This formula helps in determining the total energy consumed by a device over time.
  1. Example: Calculating Resistance Using Ohm’s Law
  • Given: V = 12V, I = 2A
  • Using Ohm’s Law: R = V/I
  • R = 12/2
  • R = 6Ω Therefore, the resistance of the conductor is 6 ohms.
  1. Example: Calculating Power in an Ohmic Conductor
  • Given: V = 10V, I = 3A
  • Using the power formula: P = IV
  • P = 10 * 3
  • P = 30W Therefore, the power consumed by the conductor is 30 watts.
  1. Summary:
  • Ohmic conductors exhibit a linear relationship between current and voltage.
  • Resistance in ohmic conductors remains constant with changes in current or voltage.
  • Ohm’s Law can be used to calculate resistance, voltage, and current.
  • Power in ohmic conductors can be determined using the formula P = IV.
  • Electrical energy consumption can be calculated using the equation E = Pt.
  • Examples and equations help in understanding and applying these concepts effectively.