My Knowledge Hub

Space  and Defence   Aryabhatta Aryabhatta was the first satellite launched by India. It was named after the great Indian astronomer of the same name. Aryabhatta weighed 360kg and was launched by the Soviet Union on April 19, 1975 from Kapustin Yar using a Cosmos-3M launch vehicle. Musk Musk is developing a series of launchers, called the Falcon, which, if successful ,could significantly undercut the price routinely paid to aerospace giants Lockheed Martin Corp. and Boeing Co., to send payloads in to Orbit. Space Shuttle Orbiter Atlantis Space Shuttle Orbiter Atlantis is one of the fleet of space shuttles belonging to the US. It was the fourth operational shuttle built. Following the destruction of Challenger and Columbia, it is one of the three fully operational shuttles remaining in the fleet. The other two are Discovery and Endeavour. METSAT METSAT was an Indian (ISRO) meteorological, geostationary satellite designed to simultaneously obtain atmospheric cloud cover, wa...

Chemical  Change And Physical Change solution: Physical changes are changes affecting the form of a chemical substance, but not its chemical composition. Physical changes occur when objects or substances undergo a change that does not change their chemicalcomposition. This contrasts with the concept of chemical change in which the composition of a substance changes orone or more substances combine or break up to form new substances. In general a physical change is reversibleusing physical means. For example salt dissolved in water can be recovered by allowing the water to evaporate.   Reactants must be moving fast enough and hit each other hard enough for a chemical reaction to take place.Increasing the temperature increases the average speed of the reactant molecules.As more molecules move faster,the number of molecules moving fast enough to react increases, which results in faster formation of products.

Particles Particles that are smaller than the atom are called subatomic particles. The three main subatomic particles thatform an atom are protons, neutrons, and electrons. The center of the atom is called the nucleus.The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. The positron has anelectric charge of +1e, a spin of ½, and has the same mass as an electron. कण  कण जो परमाणु से छोटे होते हैं, उन्हें उप-परमाणु कण कहा जाता है।  परमाणु के तीन मुख्य उप-परमाणु कण प्रोटॉन, न्यूट्रॉन और इलेक्ट्रॉन हैं।  परमाणु के केंद्र को नाभिक कहा जाता है। पॉज़िट्रॉन या एंटीलेक्ट्रॉन एंटीपार्टिकल या इलेक्ट्रॉन का एंटीमैटर समकक्ष है।  पॉज़िट्रॉन में it 1e का एनेटिक चार्ज, and का एक स्पिन है, और एक इलेक्ट्रॉन के समान द्रव्यमान है।

Element An element is a material that consists of a single type of atom, while a compound consists of two or more types ofatoms.The nucleus is the very dense region consisting of protons and neutrons at the center of an atom. It was discoveredin 1911 as a result of Ernest Rutherford's interpretation of the 1909 Geiger–Marsden gold foil experiment. Theproton–neutron model of the nucleus was proposed by Dmitry Ivanenko in 1932. Almost all of the mass of anatom is located in the nucleus, with a very small contribution from the electron cloud. तत्त्व  एक तत्व एक ऐसी सामग्री है जिसमें एक ही प्रकार का परमाणु होता है, जबकि एक यौगिक में दो या दो से अधिक प्रकार के परमाणु होते हैं। नाभिक एक परमाणु के केंद्र में प्रोटॉन और न्यूट्रॉन से मिलकर बहुत घना क्षेत्र है।  1909 की अर्नेस्ट रदरफोर्ड की व्याख्या के परिणामस्वरूप इसे 1911 में खोजा गया था।  द न्यूट्रीस के न्यूट्रॉन-न्यूट्रॉन मॉडल को दिमित्री इवानेंको द्वारा 1932 में प्रस्तावित किया गया था। एनाटोम के लगभग सभी द्रव्यमान नाभिक में स्...

Boiling Point The boiling point of a liquid is the temperature at which its vapor pressure is equal to the pressure of the gas above it.The normal boiling point of a liquid is the temperature at which its vapor pressure is equal to one atmosphere (760 torr).The boiling point of a liquid varies depending upon the surrounding environmental pressure. A liquid in a partial vacuum has a lower boiling point than when that liquid is at atmospheric pressure. A liquid at high pressure has a higher boiling point than when that liquid is at atmospheric pressure. For a given pressure, different liquids boil at different temperatures. क्वथनांक  किसी तरल पदार्थ का क्वथनांक वह तापमान होता है जिस पर उसका वाष्प दाब उसके ऊपर की गैस के दबाव के बराबर होता है। एक तरल का सामान्य क्वथनांक वह तापमान होता है जिस पर उसका वाष्प दाब एक वायुमंडल (760 torr) के बराबर होता है।  तरल का क्वथनांक आसपास के पर्यावरणीय दबाव के आधार पर भिन्न होता है।  एक आंशिक वैक्यूम में एक तरल पदार्थ की तुलना में कम उबलते बि...

Refrigerator  A refrigerator is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room. Refrigeration is an essential food storage technique in developed countries. The lower temperature lowers the reproduction rate of bacteria, reducting the rate of biochemical reactions so the refrigerator reduces the rate of spoilage. A refrigerator maintains a temperature a few degrees above the freezing point of water. Optimum temperature range for perishable food storage is 3 to 5 °C (37 to 41 °F).[1] A similar device that maintains a temperature below the freezing point of water is called a freezer. फ्रिज  एक फ्रिज एक सामान्य घरेलू उपकरण है जिसमें एक थर्मल इंसुलेटेड कम्पार्टमेंट और एक हीट पंप (मैकेनिकल, इलेक्ट्रॉनिक या क...

Cryogenic Rocket Engine Cryogenic Rocket Engine A cryogenic rocket engine is a rocket engine that uses a cryogenic fuel or oxidizer, that is, its fuel oroxidizer (or both) are gases liquefied and stored at very low temperatures.Notably, these engineswere one of the main factors of NASA's success in reaching the Moon by the Saturn Vrocket. क्रायोजेनिक रॉकेट इंजन  क्रायोजेनिक रॉकेट इंजन एक रॉकेट इंजन है जो क्रायोजेनिक ईंधन या ऑक्सीडाइज़र का उपयोग करता है, अर्थात इसका ईंधन ऑर्किडाइज़र (या दोनों) गैसों को द्रवीभूत किया जाता है और बहुत कम तापमान पर संग्रहीत किया जाता है। संभवतः, ये इंजन पहुँचने में नासा की सफलता के मुख्य कारकों में से एक हैं।  शनि व्रत द्वारा चंद्रमा।

National Aeronautics and Space Administration (NASA) : The National Aeronautics and Space Administration (NASA) is the United States government agency responsible for the civilianspace program as well as aeronautics and aerospace research. NASA’s Jet Propulsion Laboratory is located in Pasdena.Deep impact is a NASA space probe, designed to study the composition of the interior of the Comet 'Tempel-1'. Phoenix was a robotic spacecraft on a space exploration mission on Mars under the Mars Scout Program. The Phoenix lander descended on Mars on May 25, 2008. Mission scientists used instruments aboard the lander to search for environments suitable for microbial life on Mars, and to research the history of water there. The total mission cost was about US $386 million, which includes cost of the launch. राष्ट्रीय वैमानिकी और अंतरिक्ष प्रशासन (नासा)  नेशनल एरोनॉटिक्स एंड स्पेस एडमिनिस्ट्रेशन (NASA) संयुक्त राज्य अमेरिका की सरकारी एजेंसी है जो नागरिक क्षेत्र कार्यक्रम के साथ...

Internet The Internet is a global network connecting millions of computers. More than 190 countries are linked into exchanges of data, news and opinions. According to Internet Live Stats, as of December 30, 2014 there was an estimated 3,037,608,300 Internet users worldwide. The number of Internet users represents nearly 40 percent of the world's population. The largest number of Internet users by country is China, followed by the United States and India.In September 2014, the total number of websites with a unique hostname online exceeded 1 billion. This is an increase from one website (info.cern.ch) in 1991. A local area network (LAN) is a group of computers and associated devices that share a common communications line or wireless link to a server. A database is an organized collection of data. The data is typically organized to model aspects of reality in a way that supports processes requiring information, such as modelling the availability of rooms in ...

Smiling Buddha    Smiling Buddha  was the assigned code name of India's first nuclear weapon explosion on 18 May 1974. The device was detonated on the army base Rajasthan Pokhran Test Range by the Indian Army under the supervision of several key Indian army personnel. India became sixth country to have tested nuclear bombs and joined the elite nuclear club in 1998 as On 11 May 1998, 24 years after the first operation, the Atomic Energy Commission of India and the Defence Research and Development Organisation (DRDO) carried out the joint operation, known as Pokhran-II in Pokhran city of Rajsthan.  Pokhran (also spelled Pokaran) is a city and a municipality located in the Jaisalmer district of the Indian state of Rajasthan. It is a remote location in the Thar Desert region and served as the test site for India's first underground nuclear weapon detonation. मुस्कुराते हुए बुद्ध  18 मई 1974 को मुस्कुराते हुए बुद्ध को भारत के पहले परमाणु हथियार विस्फोट का...

Horology Horology is the art or science of measuring time. Clocks, watches, clockwork, sundials, hourglasses, clepsydras, timers, time recorders, marine chronometers, and atomic clocks are all examples of instruments used to measure time. In current usage, horology refers mainly to the study of mechanical time-keeping devices, while chronometry more broadly includes electronic devices that have largely supplanted mechanical clocks for the best accuracy and precision in time-keeping. घड़ी निर्माण कला  समय को मापने की कला या विज्ञान है।  घड़ियां, घड़ियां, घड़ी की कल, सुंडिया, घंटा, क्लेप्सिड्रा, टाइमर, समय रिकार्डर, समुद्री कालक्रम, और परमाणु घड़ियां सभी उपकरणों के उदाहरण हैं जो समय को मापने के लिए उपयोग किए जाते हैं।  वर्तमान उपयोग में, हॉरोलॉजी मुख्य रूप से मैकेनिकल टाइम-कीपिंग डिवाइसेस के अध्ययन को संदर्भित करता है, जबकि क्रोनोमेट्री में अधिक व्यापक रूप से इलेक्ट्रॉनिक डिवाइस शामिल हैं, जिन्होंने टाइम-कीपिंग में सर्वोत्तम सटीकता और परिशुद्धता के लिए मुख्य रूप...

Water Jet Cutter: A water jet cutter, also known as a water jet or waterjet, is an industrial tool capable of cutting a wide variety of materials using a very high-pressure jet of water, or a mixture of water and an abrasive substance. वाटर जेट कटर:  एक वॉटर जेट कटर, जिसे वॉटर जेट या वॉटरजेट के रूप में भी जाना जाता है, एक औद्योगिक उपकरण है जो पानी के बहुत उच्च दबाव वाले जेट, या पानी और एक अपघर्षक पदार्थ का उपयोग करके विभिन्न प्रकार की सामग्री को काटने में सक्षम है।

Nanotechnology            Nanotechnology is science, engineering, and technology conducted at the nanoscale, which is about 1 to 100 nanometers. Physicist Richard Feynman, the father ofnanotechnology. In the International System of Units, the prefix "nano" means one-billionth, or 10-9; therefore one nanometer is one-billionth of a meter. It’s difficult to imagine just how small that is, so here are some examples: • A sheet of paper is about 100,000 nanometers thick • A strand of human DNA  is 2.5 nanometers in diameter • There are 25,400,000 nanometers in one inch • A human hair is approximately 80,000- 100,000 nanometers wide • A single gold atom is about a third of a nanometer in diameter • On a comparative scale, if the diameter of a marble was one nanometer, then diameter of the     नैनो टेक्नोलॉजी:             नैनो टेक्नोलॉजी नैनोस्केल पर आयोजित विज्ञान, इंजीनियरिंग और प्रौद्योगिकी है, जो लग...