Category Electricity

Why is it said that Joseph Swan, along with his contemporaries, made a significant change in electric bulb?

          Another person who made significant contributions to the making of the electric bulb is Sir Joseph Wilson Swan.

          Swan was an English chemist. During the 1850s and 1860s, he conducted many experiments on bulbs using carbon filaments. Most of them failed, because the vacuum pumps used in those times were not good, so they couldn’t remove enough air from the lamps. Besides, the lamp deposited a dark layer of soot in its inner surface. This obscured the light.

          In 1878, Swan demonstrated an improved working lamp. It had a better vacuum, and carbonized thread as a filament. The method of processing was such that the bulb avoided early blackening. Soon after the demonstration, Swan was granted a UK patent. After that, light bulbs were installed in homes in England. In 1880, he received a US patent too.

              For his contributions, Swan was knighted in 1904. The same year he also received the prestigious Hughes Medal, instituted by the Royal Society of London. 

Why is it said that Edison’s contribution to the development of the electric bulb is unmatchable?

          We saw that during the 1800s, many inventors have worked hard to develop an effective light bulb. But, the most successful among these inventors was Thomas Alva Edison.

          Edison’s serious research into making a practical incandescent lamp began around 1878. He wanted to invent a safe, yet cheap electric light that could replace the earlier ones. Between 1878 and 1880, he conducted many experiments, with carbon filaments, platinum, and other metals. In 1879, he successfully tested a bulb with a carbon filament that lasted 13.5 hours.

          The following year, Edison and his team discovered that a carbonized bamboo filament could last over 1200 hours. This marked the beginning of commercially made light bulbs in 1880.

          As we know, this is just one of the many inventions made by Edison.

          Thus, Edison’s contributions remain unparalleled and, for his tireless work, he was rightfully described as one of the greatest inventors. 

Who invented light bulbs with tungsten filaments that are widely used today?

Scientists and inventors have used a number of filaments for incandescent bulbs in the past. But today, the most popular one is the tungsten filament.

It was William David Coolidge, who developed a method to manufacture tungsten filaments in 1910.

The biggest advantage of tungsten was that it had a high melting point, and was able to withstand heat and corrosion. That is exactly what attracted inventors to it. Besides, using inert gases inside the bulb increased its luminescence.

As years passed, the element was used in other lamps too, including halogen, fluorescent, mercury vapour etc. Tungsten is perhaps the most durable type of filament used in bulbs even today.

It is said that Thomas Alva Edison himself knew that tungsten would prove to be the best choice for filaments. But in his day, the technology and machinery required to produce the wire in fine form was not available.

How is a fluorescent lamp different from an incandescent lamp?

          As you may already know, incandescent and fluorescent are two types of light bulbs commonly used for various lighting applications.

          Incandescent light bulbs are older, but are still used in our houses. They come in the form of a glass sphere, with a very thin filament inside. It is the tungsten filament that we mostly use now, and it is surrounded by an inert gas. In these bulbs, light is produced by heating the metallic filament until it starts to emit light.

         A fluorescent bulb is totally different. It is a glass tube coated with phosphorous, containing mercury vapour. When the gas inside is excited, these lamps produce light. Unlike incandescent lights, they come in different shapes and sizes.

 

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What makes compact fluorescent lamp an energy saving option?

        A compact fluorescent light (CFL) bulb or lamp is a type of fluorescent lamp that is designed to replace incandescent lamps. They are known by different names – as compact fluorescent light, or energy-saving light, or as compact fluorescent tube. CFLs come in different shapes and forms, and are primarily known for their effectiveness and long life.

        The modern, spiral shaped CFL bulb that we use today in our houses was developed by Edward Hammer in the late 1970s.

        Although there are different reasons why people use CFLs, the most important feature of these lights is their ability to save energy. It is said that they consume 75 per cent less energy compared to incandescent lamps.

        Compared to ordinary lights, CFLs are more expensive, but they last longer. One can use them for months together, but not ordinary bulbs.

 

 

Why is an ammeter important?

         An ammeter is an instrument used to measure the flow of electric current in a circuit. It measures current in terms of amperes, which is the unit of current. The speed and force of a current can be measured using this instrument.

         In the past, the instrument relied on the Earth’s magnetic field to take the readings of current. But as technology improved, better ammeters were designed and developed. Ammeters are mostly used in science laboratories. Other than scientists, electricians also use this instrument, to check the electric circuit.

        There are smaller units of reading to amperes, namely, milliamperes and microamperes. These are measured using milliammeters and microammeters respectively.

        There are two types of ammeters – analogue and digital. In analogue ammeters, there is a needle that points to the reading. In digital ammeters, they are displayed digitally.