How does the concept of electromagnetic induction underpin the operation of transformers, and what are the implications for power transmission efficiency?
The correct answer and explanation is:
Electromagnetic induction is the process where a changing magnetic field induces an electric current in a conductor. This principle is crucial to the operation of transformers. A transformer consists of two coils of wire, the primary coil and the secondary coil, wound around a common core. When alternating current (AC) flows through the primary coil, it generates a changing magnetic field. This magnetic field passes through the core and induces a current in the secondary coil due to electromagnetic induction. The amount of induced voltage in the secondary coil depends on the ratio of the number of turns in the primary coil to the number of turns in the secondary coil, a relationship known as the turns ratio.
In a transformer, the input voltage in the primary coil can be stepped up or stepped down in the secondary coil, depending on the turns ratio. If the secondary coil has more turns than the primary, the voltage is increased (step-up transformer). If the secondary coil has fewer turns, the voltage is decreased (step-down transformer). This ability to change voltage is essential for efficient power transmission.
Power transmission efficiency is significantly impacted by transformers. High-voltage transmission reduces energy losses during transmission. When electricity is transmitted over long distances, energy losses occur primarily due to resistance in the transmission lines. By using transformers to step up the voltage, the current is reduced, and consequently, the energy lost as heat in the wires is minimized. At the destination, another transformer steps down the voltage to a level suitable for use in homes and businesses. This process ensures that electricity can be transmitted efficiently over long distances without excessive loss, making the distribution of electrical power more cost-effective and reliable.