IN SIDE THE ELECTRICAL CIRCUIT

We know, water flows from a reservoir down to the sea through its path as a river. In an electrical circuit, a battery is the reservoir of negatively charged electrons. There is a surplus of electrons in the negative end and there is a want of electrons on the positive side. Hence the electrons want to flow back to the battery (from negative to positive through a wire). Here, the electrons circulate. Hence the name 'electrical circuit'. Even though the electrons flow from the negative end to the positive end, the conventional current is taken to flow from positive to negative. Since the electrons are negatively charged.
Let us now come to its working. The current - electrons start from negative; it immediately encounters an obstacle called resistance R1; the electrons can not cross the resistance easily, so pressure builds up; we say a voltage develops across the resistance R1. Somehow, some current manage to pass through the resistance according to ohm's law "current = Battery voltage/resistance". [It is like a river encountering the dam, water pressure increases because of the dam-wall. Once the water touches the brim of the dam, some water overflows it]. When the current reaches the junction J1, it sees two paths with resistors. It split itself and flows in two paths according to the resistances in the paths. At the junction J2, the split current joins up and flows back to the battery. The flow of current persists as long as there is power in the battery. The resistors have voltage across them, so they act as secondary sources of electrical current. Using resistors, we can manipulate current and voltage in a circuit and tap them according to our needs. Instead of resistors, we can connect 'loads' like LEd lamp, motor, and other electrical elements and make the circuit more functional. A circuit is live and functional as long as electrons run in it.

W hen the current flows through the resistor, it heats up.

When the current flows through the coil, a magnetic attraction develops.

when the current flows through a capacitor, it stores up electricity for some time.

when the current passes through LED, it lights up.

Hence useful electrical circuits can be constructed using the above elements.

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THE EARTH, A SUPER ORGANISM

JOIN MY COURSE: "Become a programmer in a day with python" A man called 'love lock' (what a name) proposed a theory called Gaia theory, named after Greek Goddess. It says, "Earth is a self-regulating organism like a human being. The organic life in it interacts with in-organic matter and maintains atmosphere, temperature and environment". Hence the earth is still suitable for the life to thrive. Imagine, in a particular place, there are lot of flowers. Some flowers are white and some are darkly coloured. We know, white reflects light and heat while dark absorbs the same. White flowers can thrive in hot climate. But dark flowers requires cold climate. The absorption and reflection balances and the environment reaches average, warm temperature at which both the flowers can co-exist. This is the essence of "Gaia" theory. On our earth, the oxygen constitute 20% of the atmosphere. The oxygen level is always mai

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A jet of water shooting from a hose pipe will follow a parabolic path. What is the so special about parabola. Y= x^2 Draw a graph for the above equation. It will result in a parabola. This parabola is also called unit parabola. Any equation involving square will yield a parabola. Example: Y = 2x^2 +3x+3 (also called quadratic equation) X= 2 and -2, both satisfies the equation 4 = X^2. Parabolic equations always have two solutions. Any motion taking place freely under gravity follows parabolic path. Examples: An object dropped from a moving train, A bomb dropped from flying plane, A ball kicked upwards. If a beam of light rays fall on the parabolic shaped mirror, they will be reflected and brought to focus on a point. This fact is made use of in Dish Antenna, Telescope mirrors, etc. Inverted parabola shape is used in the construction of buildings and bridges. Because the shape is able to bear more weight. A plane

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Imagine a balloon full of air. The air molecules are moving randomly inside the balloon. Let us pierce the balloon with a pin. The air rushes out. Why should not the air molecules stay inside the balloon safely and ignore the little hole? That is not the way the world works. The molecules always "want to occupy as many states as possible". Hence the air goes out in the open to occupy more volume. The things always goes into disorder (entropy) and the disorder increases with time. The above statement is what we call "second law of thermodynamics". Consider a cup of coffee on the table. Suppose the heat from entire room flows to your cup of coffee, the coffee will boil and the rest of the room will freeze. Freezing means bringing things to order and arrangement. It violates the second law. Hence it will never happen. Hence heat must flow from high temperature to low temperature and not the other way. The air molecules in y

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