Fundamental Principles and Everyday Uses of DC Current
Whenever the charge flows in a closed circuit with respect to time, there generates current in that circuit. This current is divided into two types on the basis of type of flow of charge. If it flows only in one direction, it is known as direct current or DC, and if it changes its position periodically, it is known as alternating current or AC.
Simple Electric Circuit in Which Current Flows
What is DC Current (Direct Current)?
DC or direct current is the type of current which keeps on flowing in only one direction in the circuit. The current that flows in appliances which work on batteries, the current flowing in flashlights is direct current.
Direct Current Examples
Some of the examples of devices that use DC current are mobile phones, laptop, flashlights, microwave, etc.
Mobile Phone
Flash Light
List of AC and DC Appliances
Many appliances can not take direct current and therefore direct current is converted into alternating or AC current before supplying it to them. All appliances do not work on AC or on DC, different appliances are designed in different ways, based on their usage and power requirements. Some of them work on AC power supply while some of them work on DC power supply. Let’s have a look on the list of AC and DC appliances.
AC Appliances:
Microwave oven
Dishwasher
Toaster
Coffee pot
Washing machine
Refrigerator
Air cooler
Cloth dryer
DC Appliances:
Head lights
Screen wipers
Torch
TV remote controller
DC motors
Cell phones
Why is DC Current Useful?
DC current is of great use as it provides a constant current to the appliance, i.e., without changing its direction, which in turn gives better output and works efficiently.
Where is DC Current Used?
A DC motor is used to obtain or generate DC current. It is used in various appliances, some of them, which we use in our daily routine, are flashlights, TV remote, headlights of cars, etc.
Solved Questions
1. What are the two types of current electricity?
Ans: AC and DC currents are the two types of current electricity.
2. Where is DC current used in cars?
Ans: In the windshield wipers of cars, DC motors the DC current is used.
3. What do you understand by AC current?
Ans: AC or alternating current is a type of current which changes its direction of flow over a period of time.
Summary
There are two types of current namely AC (Alternating Current) and DC (Direct Current) based on the direction of current flow. DC current is difficult to transport over long distances due to power loss issues, therefore in order to transmit the current, it is converted into AC current. DC current is safer than AC current and provides more efficient output in appliances. It is employed in various industries and tools in our day-to-day lives.
FAQs on Overview of DC Current
1. What are the most common uses of DC current in our daily lives?
Direct Current (DC) is essential for most portable and low-voltage electronics. Its primary uses are found in devices powered by batteries, such as:
Mobile phones, laptops, and tablets.
Remote controls, torches, and digital cameras.
Electric vehicles (EVs) and their battery systems.
Powering components in cars, like the ignition system and radio.
Energy from solar cells and fuel cells is also generated as DC.
2. Why are most electronic devices like laptops and smartphones powered by DC current?
Electronic devices rely on sensitive components like microchips, transistors, and processors that require a steady, constant voltage to function correctly. DC provides this stable, one-directional flow of energy. The fluctuating, reversing nature of AC (Alternating Current) would be unsuitable and would likely damage these delicate internal circuits.
3. What is the main difference between AC (Alternating Current) and DC (Direct Current)?
The fundamental difference lies in the direction of electron flow. In Direct Current (DC), electrons flow steadily in a single direction, from negative to positive. In Alternating Current (AC), the flow of electrons periodically reverses its direction, oscillating back and forth at a specific frequency (e.g., 50 Hz in India).
4. If our homes are supplied with AC, how do our DC-powered electronics work?
Our electronic devices use a component called an adapter (the blocky plug for your laptop or phone charger). Inside this adapter is a circuit called a rectifier. The rectifier's job is to convert the high-voltage AC from the wall socket into the low-voltage DC that the device's internal circuits need to operate safely.
5. Why is AC current used for long-distance power transmission instead of DC?
AC is preferred for long-distance transmission because its voltage can be easily and efficiently changed using transformers. Power companies 'step up' the voltage to extremely high levels for transmission, which significantly reduces power loss over long wires. The voltage is then 'stepped down' by local transformers before entering homes. Changing DC voltage is much more complex and less efficient, making it impractical for large-scale power grids.
6. Can a device designed for DC current run on an AC supply?
No, connecting a DC device directly to an AC supply would almost certainly destroy it instantly. The device's components are built for a steady, low, one-directional voltage. The constantly reversing polarity and higher effective voltage of an AC supply would overwhelm and permanently damage these sensitive circuits.
7. Who is credited with the invention and promotion of DC current?
Thomas Edison is the most famous proponent and inventor associated with the commercial application of Direct Current. His work in the late 19th century led to the establishment of the first electrical grids based on DC power. This famously led to the 'War of the Currents' with Nikola Tesla, who championed the more efficient AC system for power distribution.
