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The water powered clock might be a surprise for newbies. Noting down the opinion of many people, they believe the ‘water’ here we use, is working as a battery. So the question arises: How does it works?

The water clock that you buy itself is an battery cell. Water doesn’t produce any electricity. It just work as an electrolyte here. Chemistry fans will know, electrolyte is a liquid that contains ions and can flow ... Read more »

Added by: Shawon, 2015-04-22

Victims to severe epilepsy, a central nervous disorder, will be lucky because of the engineers to find a new way of destroying it. Currently, those are sometimes treated by drilling into the skull, to reach the bottom of the brain and destroy the small area where the seizures originate. This is an invasive and dangerous way and needs long healing time.

Surgeons can take a shortcut to that area through the cheek to get the brain. It& ... Read more »

Added by: Shawon, 2015-04-22

Earth’s magnetic field is build in the heart of the planet which helps in navigation and solar wind.  But what protects us from the dangerous radiation is not stable. The magnetic field changes its direction by exchanging the position of north pole and south pole.

It is not that it is only happening now, scientist says in the distant past, the magnetic field changed it direction every 5 million years. But now it does more often, like every 200,000 years. This proves that the magnetic field is losing its stability. According to a BBC news article, there have 170 magnetic pole reversals in 100 million years and the major one was 781,000 years ago.

Magnetic field is generated by interaction in planet’s core and electrical currents. The bottommost part of the core is the hottest. By means of convection current, the hot i ... Read more »

Added by: Shawon, 2015-04-22

"Where did we come from?" - is the oldest and the most asked question by philosophers, mathematicians, physicist and even poets. There's no confirmed reason in science but majority scientists believed that we began from at a moment known as the Big Bang, 14 billion years ago. But how do we find any clue that this actually happened? I will show some.

The key of the theory of Big Bang is expanding. Every material was once gathered together. After the occurrence of Big Bang it expanded and formed many stars and galaxies. When we look at the night sky, the stars we can see are within our own galaxies. There are some fuzzy patches too, which other galaxies. Almost all of this are moving away from us at incredible speed - some at hundreds of thousands of kilometers every second. This means the Universe is expanding.

After ... Read more »

Added by: Shawon, 2015-04-22

Technology has made a huge difference in all sides in this world. All of these things were intended to create a better, convenient, and comfortable life. And now we are enjoying it. By researches we found lots of side-effects that contribute the planet to destruction and thus many people admits to stop many use of devices. The answer to the question,” Has technology made world a better place to live?” will be discussed here.

Firstly, by means of vehicles, airplane, we are able to travel to place swiftly saving time, energy and money. Not only that, internet and smart phones let us to contact people over millions of distance miles as if we are face to face. This helps us in developing strong relationships with one another.

Secondly, Technology made life more comfortable. If we turn on an air-condition, we no longer feel the extreme high temperature or severe cold outside. This made a heaven inside a hell. Moreover, talking about an elevator, we can reach a ... Read more »

Added by: Shawon, 2015-04-22

Hooke’s law

Hooke’s law states that when an object is stretched, its extension is directly proportional to the load force. Hooke’s law only applies if you do not stretch an object beyond its elastic limit.

Newton’s Law of Motion: 1st Law

An object will continue in a state of rest or uniform motion in a straight line unless an external force acts upon it.

Newton’s Law of Motion: 2nd Law

The rate of change of momentum of an object is directly proportional to the force acting and takes place in the direction in which the force acts.

Newton’s Law of Motion: 3rd Law

Every action has a equal and opposite reaction.

Ohm’s law

The current flowing in a metallic conductor is directly proportional to the potential difference applied across its ends, provided that the physical conditions are constant.

Law of Reflection

i.Th ... Read more »

Added by: Shawon, 2015-04-22

Forest is the area which is chiefly covered by trees. In the recent years, people have been indulged to destroy forest areas and replace them with things they need, not knowing the importance of forests. Consequently, forests are still being cut down.

Here, we will discuss about the importance of forests to aware people why to conserve plants and trees:

Gives Oxygen: The most important part of forests is its distribution of oxygen among the earth. Almost all oxygen comes from forest. Animals and plants are dependent on each other. Animals provide carbon dioxide - which plant need for photosynthesis and gives out oxygen - which animals need for respiration. Thus, forests are being termed as the "Lung of the Earth”. 

Homes of creatures: Forests are the home of millions of creatures and more than three-fourth animals in the world. This makes them the world’s richest biological system.

... Read more »

Added by: Shawon, 2015-04-22

Energy in stars are formed by the fusion reactions in the core of the stars which produce enormous energy and glows stars hot and bright. Hydrogen is the main fuel of stars.

 

Nuclear fusion is the reactions of nuclei combining together to form heavier nuclei. During the fuse, lots of energy is given out as heat and light. Combining nuclei will form a new element. Deep in its core, the heat output and huge gravitational pull keep the hydrogen hot enough and compressed enough to maintain fusion. In sun, nuclear fusion occurs only at 15 million degrees

Nuclear reactions depends on the size of stars.

Small stars: The smallest stars only conv ... Read more »

Added by: Shawon, 2015-04-22

Rule 1: Identify the cations and anions in the electrolyte. Remember that an aqueous solution also contains H+ and OH- ions from the dissociation of water molecules.

Rule 2: At the anode, the product of electrolysis is always oxygen unless the electrolyte contains a high concentration of the anions, Cl-, Br- or I- ions.
Rule 3: At the cathode, reactive metals such as sodium and potassium are never produced during electrolysis of the aqeous solution. If the cations come from a metal above hydrogen in the reactivity series, then hydrogen will be liberated. If the cations come from a metal below hydrogen, then the metal itself will be deposited.
Rule 4: Identify the cations and anions that remain in the solution after electrolysis. They form the product remaining in solution. Summarise the reactions.
Added by: Shawon, 2015-04-22

Independent variable: It is the variable that the experimenter changes, to get different values from dependent variable.

Dependent variable: The variable that depends on independent variable.

Controlled variable: The variable that doesn’t actually affect anything.

How to identify these variables?

Let’s take a look on a past question paper from IGCSE Physics 2013 Jan Paper 1.

Q: A student investigates how the resistance of a wire depends on its length. The photograph shows the circuit that the student uses. Identify the independent and dependent variable.

One easy technique to find the answers is to check what variable t ... Read more »

Added by: Shawon, 2015-04-20

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