Dr Rajiv Desai
An Educational Blog
MONEY
Money: _ ____ Section-1 Prologue: Somebody once asked the late bank robber named Willie Sutton why he robbed banks. He answered: “That’s where the money is.” Money is something we encounter in every facet of our daily lives. The first thing that springs to mind for most of us when we hear the word “money” is coins and banknotes. We talk about “making money” when we refer to our income. We say that we are “spending money” when we go shopping. For major purchases we sometimes have to “borrow money” by taking out a loan, either from someone we know or from a bank. It is no accident that the term “money” gets used in so many different ways: it is a reflection of the myriad functions that money performs in our economic lives. _ Money is one of the fundamental inventions of mankind. Economists say that the invention of […]
The Chip
The Chip: _ Figure below shows chip manufacturing facility: ______ Section-1 Prologue: More than 100 years ago, humans invented vacuum tubes that made electricity flow in different directions or get stronger. The tubes made it possible to invent radios, televisions and computers. Every electronic device like a computer and radio works by controlling and manipulating the flow of electric current through a network of interconnected elements like capacitors, diodes and transistors. Before the invention of the chip, electronic devices such as computers and radios used vacuum tubes, or valves, which were cumbersome, heavy and generated a large amount of heat while consuming a lot of power. A 1940s computer called the ENIAC with vacuum tubes about the size of an adult thumb was about the same length and weight as three to four double-decker buses and contained 18,000 vacuum tubes, 7,200 crystal diodes, 1,500 relays, 70,000 resistors, 10,000 […]
HYDROGEN
Hydrogen: _ _ Section-1 Prologue: Primary energy sources include fossil fuels (petroleum, natural gas, and coal), nuclear energy, and renewable sources of energy. Energy carriers include electricity and heat as well as solid, liquid and gaseous fuels. They occupy intermediate steps in the energy-supply chain between primary sources and end-use applications. Energy carriers allow the transport of energy in a usable form from one place to another. Hydrogen is an energy carrier, not an energy source and can deliver or store a tremendous amount of energy. Hydrogen is the chemical element with the symbol H and atomic number 1. H is in the upper left corner of the Periodic Table. Hydrogen is the most basic chemical element — just one proton and one electron — and makes up nearly three-quarters of the mass in the universe. Stars such as the Sun are mainly composed of […]
DRONE
DRONE: _ Section-1 Prologue: The term “Drone” has been massively overused; most of you have surely seen it time and time again in news and media articles. This term can range from small and cheap hobby aircraft available at Amazon all the way to multimillion weapons systems used on battlefields. Drone is a general term, not a technical one. They are generally equated with unmanned aerial vehicles (UAVs). UAVs can be controlled remotely or autonomously. When we speak about drones, we think about a battlefield, destruction, and death. This is because of the fact that the drones have been conventionally used by the armed forces to drop bombs and destroy enemy targets. These are called the military drones. According to the Bureau of Investigative Journalism, there have been at least 14,040 confirmed drone strikes between Jan. 2002 and Jan. 2019. UAVs are an emerging technology known for their […]
FOOTWEAR
FOOTWEAR: _ _ Section-1 Prologue: Shoes are a product of everyday use that everyone in the world owns; there are more than 20 billion pairs of shoes manufactured each year. Shoes have come a long way in the thousands of years since primitive man first donned bark and animal skins. Originally used to protect feet from harsh temperatures and rough land, shoes have evolved into an article of high fashion and style, a sartorial reflection of class, rank, and wealth. Most people think that wheel invention was the greatest event of the ancient time, but shoemaking takes a very high position on that list too. As they say, “you are what you wear.” And there’s a lot that shoes can tell us about a person. Shoes make the man, they say. Throughout human history, we’ve improved, embellished and refined footwear. We’ve created shoes that impress and inspire, and shoes […]
