How does a fluorescent tube work?

All of you must have seen a fluorescent tube light at home, school or other places. Even though other lights are coming through, fluorescent tube gives you bright yet soothing light at reasonable low power consumption. Ever wondered how a fluorescent tube giving us the bright light? Do you want to know its working principle? Your physics tuition will just do that for you. So, let us understand the basic working principles of fluorescent tube light. In today’s physics tuition you will learn how a fluorescent tube light works.

Man has been using artificial lighting since old times. The revolutionary invention in this field was that of electric bulb in 1878 by Thomas Edison. By 1930, the scientists of America and Europe have developed the wonderful fluorescent tube.

A fluorescent tube consists of a long tube made of glass and coated inside with some fluorescent materials. There are two tungsten electrodes fitted at the ends of this glass tube. The glass tube is evacuated and then filled up with a small quantity of argon gas and mercury. When the connection of the tube is made with an electric line, the electrodes made of tungsten get heated up thereby starting to produce electrons. The electrons, thus produced then collide with the atoms of mercury and generate visible and ultraviolet light. Ultraviolet light on colliding with fluorescent materials generate visible light. These generated lights may have different colors depending upon the fluorescent matters used inside.

These tubes are coated with calcium tunstate to produce blue light. Similarly, a calcium silicate coating produces light of pink color, whereas green light is produced with zinc silicate. Fluorescent tubes are useful sources of light producing light of very high efficiency at relatively low electric consumption. Normally, fluorescent tube can be lighted for 40 hours with one unit of electricity. It means that it has wattage of 40 watts. We hope you enjoyed this lesson from physics tuition. We will be back with more such interesting findings in our next physics tuition.

Why do objects appear colored?

As always your physics tuition is back. Do you know why an apple or tomato appears red or the grass green, when they are illuminated by the same sunlight? Have you ever given a thought why different objects have different colors? Ever wondered why a red object is red and the blue one blue? You may think of asking this question in your physics tuition. Today in physics tuition, we will see how objects get their color? In fact, the color of an object depends upon the color it reflects.

The sunlight, which appears white, consists of seven colors. These are violet, indigo, blue, green, yellow, orange and red. These seven colors can also be seen in a rainbow. Sunlight can also be separated into seven colors with the help of a prism.

In sunlight, an apple or tomato appears red because it reflects only the red light and absorbs the rest. The grass appears green because it reflects only the green light and absorbs all other colors present in the sunlight. A white shirt seems white because it reflects all the colors of sunlight and a blackboard appears black because it absorbs all the colors of white light and reflects none. To prove this, conduct a simple experiment. Throw red light on a white shirt and you will see that it becomes red. White objects take the color of the light falling on it. Similarly, if we see an apple in red or white light it will appear red, but in green or blue light it would become black. It cannot reflect any other color, but red and, therefore, looks black in any other color except red or white. This is how the various objects get their color. We hope you enjoyed this lesson from physics tuition. We will be back with more such interesting findings in our next physics tuition.

What is the system behind the functioning of an air-conditioner?

In today’s physics tuition we will cover an interesting story that may have come into your mind. We all know about air-conditioners or AC machines that keep our self cool on a hot and humid day. How the AC machine able to cool an entire room or even a complete building or a shopping mall? Have this question ever came in your mind? How this is at all possible? Do you want to know the answer from your physics tuition? In today’s physics tuition, we will find answers to this interesting question and see how an air-conditioner keeps you cool in a hot day.
The air-conditioner is an electrically operated machine through which the houses, laboratories and industries can be kept cool during summer and warm during winter. It not only controls the temperature, but also regulates the humidity.

In general, the air-conditioner keeps the temperature between 20 degree celsius and 25 degree celsius and the relative humidity around 30 to 50 percent. An air-conditioning plant consists of a compressor and a cooling liquid like Freon gas. Cooling liquid evaporates in the cooling coil. The vapor is then carried to the electrically-operated compressor. It then goes to the condenser where it is cooled by air or water as it passes through the radiator. Here the vapor changes to a liquid, giving up heat in the process. The compressor thus serves to transfer heat from one place to another. A fan sends the fresh air into the room which keeps the room temperature at the desired degree. The air-conditioner has certain substances which remove the moisture from the room. It also has filters to remove the dust particles from the air. This is how an air-conditioner controls the temperature and humidity and keeps the air clean. We hope you enjoyed this lesson from physics tuition. We will be back with more such interesting findings in our next physics tuition.

How Binoculars Work?

Today we will learn an interesting topic during your physics tuition. Have you ever seen binoculars or monocular? Ever wondered how objects come closer when seen through a pair of binoculars? You may want to ask this question in your physics tuition. Today in physics tuition we will see how these binoculars or monocular work. Binoculars may be considered as being a pair of small telescopes mounted on a specific frame. It provides a magnified view of distant objects. In binocular there are two structurally exactly similar telescopes are present for each eye. Usually, each of these telescopes is fitted into a funnel-shaped cylinder or tube and is made of two lenses, one known as objective lens and the other one is called eyepiece. The objective lens is kept towards the object and eyepiece near the eye. The lenses are coated to prevent reflection. In between these two lenses set there are two prisms mounted that helps in making the objects erect (they are inverted without them).

At first light coming from the objects falls directly on the objective lens, thereby creating an inverted and magnified image of the object. After passing through the prisms this inverted image gets erect. Further magnification of the image is done by the eyepiece. The light finally falls on our eyes and we are able to see the magnified image of the object.

Usually, normal binoculars have single adjustable wheels or thumb screw for controlling the focus of both telescopes simultaneously. Some binoculars have separate focus wheels for each telescope for varying characteristics of the two eyes.

Two numbers are typically engraved or printed on the binocular at some place on the external cover. The first of the number represents the magnification power of the binocular whereas the second number illustrates the objective lens diameter in millimetres. If the binoculars are marked 6x35, then it will magnify an object six times through an objective lens that is 35 mm in diameter.

Binoculars provide stereoscopic vision, i.e. depth perception at greater distances as here both the eyes can be used simultaneously. People often use them to see matches in the playgrounds. Binoculars are even used in some of the sophisticated modern microscopes for clearer and three-dimensional image of the object.

We hope you enjoyed this lesson from physics tuition. We will be back with more such interesting findings in our next physics tuition.

Best Physics Tuition in Singapore

Miracle Learning Centre Pte Ltd specialises in Science and Mathematics. Other than Chemistry, Physics is another Science subject that Miracle is strong in. Physics concepts are not easy to explain and not all teachers can explain well. Physics concepts are not easy to explain and not all teachers can explain well. All our Physics teachers are NIE trained, ex-school teachers who explain concepts very clearly and are able to give examples to elaborate the Physics concept. Physics teachers need to be very well versed in the subject to be able to explain the subtle differences in the topic. They will also highlight what to take note of and to be precise in your answers and calculations.

What is Magnetism

We are back with another exciting story for your physics tuition. Your physics tuition will always come up with interesting facts about physics. About 800 B.C., a black stone was discovered in Magnesia, a province of Asia Minor. It was observed to be having a strong attraction for iron. Since it was found in Magnesia, it came to be known as a magnet. This stone was in fact an ore and is nowadays called magnetite.
In experiment, it was found that if this piece of loadstone was dipped in iron fillings and then lifted out, the fillings mainly adhered to its certain parts, the other parts remaining bare. These regions of greatest attraction were called the poles and the place where there was little attraction was called a neutral region.
It was also discovered that if a piece of loadstone was suspended by a thread or floated on a piece of wood, it came to rest in a definite direction-pointing towards north and south. The pole pointing towards the north was known as the North Pole and that pointing towards the south was the South Pole. This property was used by the Chinese in 13th century to make use of the magnets as compasses for finding the direction in the sea voyages.
The experiment in this field further revealed that if two loadstones were brought together, the north and the south poles attracted, while north-north and south-south poles repelled each other. This established the fact that dissimilar poles attracted each other and similar poles repelled each other.
If a bar of iron or steel is rubbed from end to end with a piece of loadstone, it also acquires magnetic properties and becomes a magnet. Such a magnet is known as an artificial magnet. This method was used for a long time for making artificial magnets.
Gradually the scientists working in this field also discovered that a magnet could also be made by winding an insulated wire round a piece of iron and passing an electric current through it. This is called an electromagnet. Such magnets are used in electric motors.
The next important discovery in the field of magnetism came in 1600. The English scientist, Sir William Gilbert, suggested that the earth was a giant magnet. This explained the fact why a freely suspended magnet points to the north and south of the earth.
During the next few hundred years, more discoveries were made in this regard. However, the ‘phenomenon magnetism’ was not properly understood until the 19th century.Now the scientists know that magnetism is caused by moving electrons. All matter is made up of atoms and atoms have a central core called the nucleus around which electrons revolve in different orbits. These electrons carry a negative charge. Whenever an electric charge moves, it produces a magnetic effect. The moving electrons make a substance magnet. Sometimes the magnetism of the different electrons in each atom gets neutralized, that is why some materials are non-magnetic in nature.
Magnetism occurs most strongly in three metals: iron, cobalt and nickel. These metals can be used to make strong magnets. Iron is almost always used because it is the cheapest of the three metals. Usually magnets are made of steel, an alloy of iron.
Magnets are very useful in our daily life. They are used in making the Mariner’s compass to guide the ships. They are also used in radio sets, television sets, telephones, microphones, and in many other electronic instruments. They are also used in electric generators and motors. We hope you enjoyed this lesson from physics tuition. We will be back with more such interesting findings in our next physics tuition.

Best Physics Tuition in Singapore

Miracle Learning Centre Pte Ltd is conveniently located in Bukit Timah, and started in 2008 as a centre specializing in Mathematics and Science. Because we were founded with one simple aim – “achieving excellence in mathematics and science”, we have been able to stay focused, and deliver consistent results. We must be doing something right! Physics concepts are not easy to explain and not all teachers can explain well. All our Physics teachers are NIE trained, ex-school teachers who explain concepts very clearly and are able to give examples to elaborate the Physics concept. Physics teachers need to be very well versed in the subject to be able to explain the subtle differences in the topic. They will also highlight what to take note of and to be precise in your answers and calculations.