Recap on Electrical Energy and Power

The energy generated from the potential or kinetic energy of charged particles is called electrical energy. The flow of electrons from one location to another generates electrical energy, which may be defined as the energy transferred between the two points and thus, electric power is created. The flow of charged particles via a medium (say, wire) constitutes current or electricity. Electrical energy is continually transformed into different types of energy in an electric circuit. 

Power in electrifying circuits 

Electrical energy is transformed into thermal energy inside a conductor when a current travels across it. The voltage source’s electric field accelerates the free electrons, increasing their kinetic energy for a brief period.

Many people think about power in terms of electricity. Is electric power a measure of the rate of energy used or converted? Think about electric power lines when you hear the word “transmission.” The wattage of a lightbulb is another way to describe it. Consider a 25-watt light bulb and a 60-watt light bulb. Even though they are both powered by 120 volts, the 60-watt bulb must take a bigger current to achieve its higher wattage. 

The 60-W bulb must be lower than a 25-W one to keep the bulb’s resistance low. Increasing the voltage results in an improvement in both power and efficiency. For example, when using a 25-W bulb meant to function on 120 V, it quickly lights extremely brilliantly and then burns out.

The formula for electric power

Voltage multiplied by current equals electric power (P). Watts are the standard unit of measurement for power. Power is measured in joules per second (or watts), the SI unit for potential energy (PE). Therefore, 1 A V = 1 W. Many automobiles are equipped with one or more auxiliary power outlets for charging electrical devices like cell phones. In this case, the maximum power P = IV = (20 A)(12 V) = 240 W may be delivered by these outlets. Volt-amperes or even kilovolt-amperes (1 kA V = 1 kW) may be used to indicate electric power in specific situations. Ohm’s law and P = IV combine to show how power and resistance are linked. P is equal to (V/R)V=V²/R when I = V/R is substituted. A similar result may be obtained by swapping V for IR, i.e., P = I²R. 

Listed below are three terms for electric power:

P= VI

P= V²/R

P= I²R

Only resistors may be used with the other two equations, while the first equation is always true. The power of the appliance provided by the voltage source and the power wasted by the resistor is the same in a simple circuit. The power dissipated by a single device (with more complex circuits), P might represent the overall power dissipated in the circuit. Each of the three terms for electric power provides a distinct perspective. Using the formula P = V²/R, we see that the lower the resistance, the more power is provided. The impact of a larger voltage may be more than predicted since the voltage is squared in P = V²/R. A 25-watt bulb’s wattage roughly quadruples when the voltage is doubled to around 100 watts, resulting in the bulb being burned out. The bulb’s resistance would be lower, resulting in a power output of 100 W.

Electricity prices

Energy (E) may be saved by lowering the time spent using an appliance or reducing its electric power consumption. In addition to saving money, this will also positively affect the environment. Reducing the amount of electricity consumed in a building or house may be as simple as changing the lights. Lighting accounts for around 20 percent of a home’s energy usage, while commercial organisations utilise about 40 per cent. Long-tube and compact fluorescent lighting (CFL) are more energy-efficient than their incandescent counterparts by a factor of four. 

Conclusion

Lighting fixtures made of commercial LEDs are gradually becoming the norm for business and residential lighting, rapidly replacing incandescent and compact fluorescent bulbs. They are made of gallium that has been doped with arsenic and phosphorus atoms and such device changes are intended to operate in the visible spectrum. Small LEDs seen on circuit boards in the early years of LED development were only available in three colours: red, green and yellow. Today, LEDs can be programmed to create millions of distinct colours of light and many various shades of white light.