Why AC can’t be stored in Batteries? - Student's Corner


Welcome to the ultimate hub for academic success – "Student's Corner"! 📚 Dive into a treasure trove of resources crafted by fellow students and professionals. Access notes, assignments, and question papers, all curated to elevate your learning experience. Fuel your academic journey with shared knowledge! Note: The material provided on this site is contributed by various individuals. The site owner is not responsible for the accuracy or reliability of the content. Use at your own discretion.

Subscribe Us

In the beginning there was nothing, which exploded.

Sunday, December 31, 2023

Why AC can’t be stored in Batteries?


Why AC can’t be stored in Batteries?

Voltage is accumulated within a battery, housing two fixed terminals, namely positive and negative. Direct Current (DC) voltage is storable in a battery because it can seamlessly complete the circuit within, traveling from the positive to the negative terminal. However, attempting to store Alternating Current (AC) in a battery presents a challenge. For AC storage to occur, the battery terminals would need to switch at the frequency of the AC voltage (e.g., 50 times per second). Given that the terminals of a battery are stationary, this proves impractical and serves as an extravagant proposition. The fundamental limitation arises from the fixed nature of the battery terminals. In the charging phase, the battery accumulates charge during the positive half of the voltage, only to discharge during the negative half. Consequently, the net result is zero charge within the battery.


Which is better 60 Hz or 50 Hz?

The choice between 50Hz and 60Hz frequency depends on a number of factors, including the specific electrical power transmission and distribution needs of a region, and the availability and cost of the electrical generating equipment. There is no inherent superiority of one frequency over the other.


Both 50Hz and 60Hz frequencies have been proven to be effective for electrical power transmission and distribution, and both have been in widespread use for over a century. The important thing is to ensure that the frequency is consistent and stable, as fluctuations in frequency can cause problems with the operation of electrical equipment.


Why AC can’t be stored in Batteries?
Why AC can’t be stored in Batteries?


Why Transmission lines are stranded?

Stranded wire presents a superior choice for connecting electronic components, particularly in confined spaces or intricate configurations, owing to its enhanced flexibility. Its pliability makes it ideal for navigating cramped environments, allowing for easy twisting and bending accommodating intricate geometries without compromising its structural integrity. This flexibility is particularly advantageous in applications where maneuverability is key, such as in compact electronic devices or intricate circuitry.


Compared to solid wire, stranded wire exhibits greater flexibility and malleability, allowing it to conform to the contours of various spaces without the risk of splitting or severing. This characteristic ensures a more robust and reliable connection, reducing the likelihood of damage during installation or usage. In scenarios where durability, adaptability, and resilience are crucial, the enhanced flexibility of stranded wire not only simplifies installation but also contributes to the overall reliability of electronic systems, ensuring consistent performance in dynamic and space-constrained environments.


Why might transformers have humming sound?

The humming sound produced by a transformer is primarily a result of the magnetostriction phenomenon and the alternating magnetic fields involved in its operation. Magnetostriction is the property of ferromagnetic materials to change shape or dimensions slightly when exposed to a magnetic field. Here's why transformers might produce a humming sound:

  1. Core Vibration:

Transformers have a magnetic core made of laminated sheets of ferromagnetic material, typically iron or steel. When the transformer is energized with alternating current (AC), the magnetic field in the core constantly changes direction, causing the core to undergo small, cyclic expansions and contractions due to magnetostriction. This periodic mechanical motion can produce vibrations, resulting in the humming sound.

  1. Frequency of Operation:

The frequency of the humming sound corresponds to the frequency of the alternating current passing through the transformer. For example, in many regions, the power grid operates at a frequency of 50 or 60 Hertz, and the transformer's humming sound follows this frequency.

  1. Construction and Design:

The design and construction of the transformer can influence the magnitude of the humming sound. High-quality transformers often incorporate design features and materials to minimize vibrations and noise. However, even with these measures, some level of hum may still be present.

4.   Load Conditions:

The load conditions on the transformer can affect the magnitude of the humming sound. Transformers under heavy load or experiencing fluctuations in load may exhibit increased vibrations and consequently produce a more pronounced humming noise.

While transformer humming is a normal aspect of their operation, excessive or unusual sounds may indicate a problem, such as loose laminations, mechanical issues, or electrical faults. Regular maintenance and monitoring are essential to ensure transformers operate within their designed parameters and to identify any issues that may require attention.



What is reverse polarity and why it is problematic?

Reverse polarity refers to the improper connection of positive and negative electrical wires or terminals. In a correctly wired electrical circuit, the positive (+) terminal of a device or component should be connected to the positive side of the power source, and likewise for the negative (-) terminals. Reverse polarity occurs when this connection is reversed, meaning the positive terminal is connected to the negative side, and vice versa.


Reverse polarity can be problematic for several reasons:

  1. Equipment Damage:

Many electrical devices and components are designed to operate with a specific polarity. Reversing the polarity can lead to incorrect voltage and current flow, potentially damaging or destroying the connected equipment.


  1. Malfunction of Electronic Devices:

Electronic devices often have diodes, which allow current to flow in one direction only. Reverse polarity can cause these diodes to block current flow, leading to the malfunction or failure of the device.


3.   Safety Hazards:

Reverse polarity can create safety hazards, especially in devices that rely on proper polarity for grounding or in systems where electrical components are interconnected. It may compromise the effectiveness of safety features and increase the risk of electric shock or fire.


4.   Inefficient Operation:

Some devices may operate inefficiently or not at all with reversed polarity. Motors, for example, may rotate in the opposite direction, and other electronic components may fail to function as intended.


Battery Issues:

In systems that use rechargeable batteries, connecting them with reverse polarity can damage the battery and reduce its lifespan. It may also pose a safety risk, including the potential for leakage or explosion.


To avoid issues related to reverse polarity, it's crucial to double-check and ensure correct polarity when connecting electrical components, devices, or batteries. Many electrical connectors and devices are designed with features to prevent reverse polarity, such as keying or asymmetrical connectors, but caution and proper verification are essential during installation or maintenance to prevent inadvertent mistakes.



What is difference between Alternators and Generators?

Alternators and generators are both devices that convert mechanical energy into electrical energy, but they operate on different principles and have distinct characteristics. Here are the key differences between alternators and generators:


1. Principle of Operation:

  • Generators (Dynamos): Generators operate on the principle of electromagnetic induction discovered by Michael Faraday. In a generator, a coil of wire rotates within a magnetic field, inducing an electromotive force (EMF) or voltage across the coil. This process produces direct current (DC).
  • Alternators: Alternators, on the other hand, generate alternating current (AC). They use the principle of electromagnetic induction as well but typically involve a rotating magnetic field and a stationary coil. As the magnetic field moves relative to the coil, it induces an AC voltage.

2. Type of Current Produced:

  • Generators: Produce direct current (DC), where the flow of electric charge is unidirectional.
  • Alternators: Produce alternating current (AC), where the direction of electric charge alternates periodically.

3. Commutation:

  • Generators: Require a commutator to convert the induced AC into DC. The commutator is a rotary switch that reverses the direction of current flow in the coil, resulting in a unidirectional current.
  • Alternators: Do not need a commutator, as the nature of the induced current is already AC. They use slip rings to transfer the AC output to an external circuit.

4. Voltage Regulation:

  • Generators: Typically have poorer voltage regulation compared to alternators. Voltage regulation refers to the ability of the generator to maintain a steady output voltage under varying loads.
  • Alternators: Generally exhibit better voltage regulation, making them more suitable for applications with varying loads.

5. Applications:

  • Generators: Historically, generators were commonly used for direct current (DC) applications, such as early electrical systems. They are still used in some applications where DC power is specifically required.
  • Alternators: Widely used in modern power generation systems and in most automotive applications. Alternators are preferred for their efficiency, better voltage regulation, and the ability to produce AC, which can be easily transformed to different voltage levels.