Notes: Science and Technology | GK Olympiad for Class 3 PDF Download

Introduction

Science has become an essential part of our life. We see the effect of science all around us. The development of science has resulted in technological improvement. We use many types of equipment in our daily life without sometimes understanding that these are the result of improvements and upgradation in technology.

Important Scientific Concepts

• The white light from the sun consists of seven colors: Violet, Indigo, Blue, Green, Yellow, Orange, and Red. Among these, Violet and Blue disperse the most, which is why we see a blue sky during the day when viewed from Earth. However, from space, the sky looks black.
• In the summer, we feel comfortable when the air moves because the warm air helps to absorb sweat from our skin, making us feel cooler. During the rainy season, the air is filled with water vapor and water droplets, which means it cannot take away much sweat. This causes us to feel humid and sweat more.
• The Earth has a natural force that pulls everything toward it, known as gravity. This means that when something falls, it is pulled down with the same speed. While falling, the object does not feel the weight of anything it carries.
• Even though ice is made from water, it is lighter than water, which is why it can float. However, ice is heavier than many other liquids like oil, ink, and alcohol, causing it to sink in those liquids.
• There are high-voltage electric currents in the wires that hang from electric poles. Birds can sit on these wires without getting shocked because they are only touching one wire, which means the electrical circuit is not complete. Since they are not in contact with the ground, the current cannot flow through them. However, if a bird touches two wires at once, it could receive an electric shock.
• An apple contains more enzymes that help keep a person awake than any tea or coffee available.
• Saltwater takes longer to boil than freshwater. This is why salt is added to water when cooking pulses. The salt helps the pulses cook better by allowing them to absorb more heat and become softer.

Types of Materials

The materials can be classified as:

Natural Vs. Man-made

• Objects that exist in nature and cannot be created by people are known as natural objects. 
• All other items that are made by humans are referred to as man-made objects.

Living Vs. Non-living

• Man-made items are considered non-living. 
• Natural items can be divided into living and non-living categories. 
• Things that can breathe and require food are classified as living things. 
• All other items that do not breathe or need food are termed non-living things.

Conductors Vs. Insulators

• Materials that can carry electricity or allow electric current to flow through them are called conductors. 
• Examples of conductors include metals like iron, aluminium, and steel. 
• Items that do not conduct electricity are known as insulators. 
• Common insulators include materials like wood, plastic, and air.

Energy

Energy is the ability to perform work. We obtain energy from the food we consume. Our food comes from plants and other animals. These animals also derive their energy from plants. Plants, in turn, gain their energy from the food they produce using sunlight. Therefore, sunlight is the primary source of all energy on Earth.

Types of Energy

• Potential Energy: This is the energy stored in an object because of its position or its state of rest.
• Kinetic Energy: This is the energy an object possesses when it is in motion.
• Heat Energy: This type of energy is related to temperature increases. It is used for boiling water, cooking food, and keeping warm. It comes from burning fuels like wood, coal, LPG, and CNG.
• Light Energy: This energy allows us to see things. It can come from burning fuels like wood and coal or from converting electrical energy through devices such as Compact Fluorescent Lights (CFLs), bulbs, and tube lights. The sun is the largest and most important source of light energy.
• Electric Energy: This energy powers electrical devices such as microwaves, refrigerators, air conditioners, computers, and fans.
• Wind Energy: This energy is generated from the movement of air, known as wind. It helps sail boats and turns turbines in windmills to create electricity.
• Hydel Energy: This is the energy obtained from flowing water. Water is made to flow from a height in structures called dams. The falling water turns turbines to produce electricity.
• Solar Energy: This energy is collected from the sun. Solar panels capture sunlight during the day and store it for use at night. Various solar devices, like solar cookers, solar calculators, and solar water heaters, use solar energy for different purposes.

Evolution of Gadgets

With advancements in science, we have seen quick growth in technology. This development has led to the creation of many gadgets, some of which have become essential in our everyday lives.

• Upgrades in items like cars, refrigerators, computers, mobile phones, microwaves, televisions, and washing machines represent the progress of technology.
• One major benefit of technology is the internet. During the challenging times of the COVID-19 pandemic, the internet was a great help. It allowed students to attend online classes and people to work from home. Additionally, it made online shopping and staying in touch with others much easier.

Here are some important gadgets that have been especially useful:

• Computers: There are two types of computers: desktops and laptops. Both are key sources of information as they can access data from the internet through search engines like Bing and Google. These search engines can be accessed using browsers such as Opera, Edge, Chrome, and Firefox.
• Smartphones: Originally, mobile phones were designed for communication on the go. As technology improved, features of computers were added to create smartphones. These devices can perform most functions of a computer while also allowing users to communicate via calls or social media apps like WhatsApp. They can also take pictures, record videos, and facilitate e-shopping and e-banking.
• Tablets: Tablets serve as a middle ground between mobile phones and computers. They are larger than mobile phones but smaller than laptops, combining the best features of both.
• Game Consoles: These devices provide an immersive gaming experience. They are often used as a way to relieve stress and unwind from daily routines.
• Smart TVs: Smart TVs are televisions that can connect to the internet. They allow users to watch all kinds of information and videos directly from the internet and stream channels live.
• HoloLens: Developed by Microsoft, HoloLens is a virtual reality headset featuring transparent lenses and built on a mixed reality platform called Windows Holographic.
• GPS: The Global Positioning System (GPS) is made up of a network of satellites and receivers. It helps people locate objects on Earth.

Advantages of Gadgets:

• Gadgets simplify our daily tasks.
• Gadgets help us stay connected with others, both personally and at work, by giving us access to email, text messages, phone calls, video chats, and social media.
• We use gadgets to make new friends and connections, whether online or in real life.
• Gadgets have transformed shopping, enabling online shoppers to purchase millions of items with just a tap or a click.
• Doctors can examine the inside of our bodies using gadgets such as x-rays and ultrasounds.

Disadvantages of Gadgets

• Children and teenagers are exposed to the evils associated with smartphones and other gadgets that connect to the internet. 
• Over-reliance on smartphones and other electronic gadgets leads to tech-addiction.
• There is an increased risk of identity theft and other serious crimes.
• Loss of privacy is also a disadvantage of gadgets.
• Personal photos, videos and other private data are at risk of being exposed or lost.