What is meant by Atmospheric Refraction?We can observe the apparent random wavering or flickering of objects seen through a turbulent stream of hot air rising above a fire or a radiator. The air just above the fire becomes hotter than the air further up.…

REVERSIBLE AND IRREVERSIBLE CHANGESChanges that occur around us can be broadly categorized as reversible or irreversible depending on whether or not they can be reversed.Reversible ChangesChanges that can he reversed are called reversible changes. What …

How Shadows Are FormedAn opaque object blocks the light falling on it. This creates an area of darkness on the side of the object away from the source of light. A translucent object also creates a faint area of darkness. An area of darkness formed by an …

How Does Sound TravelHave you ever thrown pebbles in a pool of water? The impact of pebbles in water creates ripples of waves that spread in the pool. In a similar fashion, vibrations cause waves in the air. We hear the sound when these waves reach our …

Examples Of Contact ForcesForces that act on objects by direct or indirect physical contact are called contact forces. Applied forces and friction are examples of contact forces.Applied Forces The forces that we use with our hands, legs, fingers, etc., …

How is apparent depth and real depth related to refractive index?Figure shows two opaque cups, A and B. Cup A is partially filled with water and cup B is totally filled with water. A similar coin is placed at the bottom of each cup. When observing from …

What Are Sources Of LightAny object that gives out light is called a source of light. Luminous objects are also called sources of light. Sources of light can be natural or artificial (man-made). Examples of natural sources of light are ‘he sun and other…

What are the Sources of Energy?If energy can neither be created nor destroyed, we should have no worries! We should be able to perform endless activities without thinking about energy resources then why we speak to save energy ? Its because energy from t…

Ways of Increasing Friction and Reducing FrictionMethods of Reducing frictionWear and tear due to friction depends on two factors: the roughness of the two surfaces in contact and the amount of time the two surfaces rub against each other. Wear and tear…

What Is An Electrical FuseWhat will happen if a large amount of electric current passes through an appliance? It causes the wires to get overheated, and the appliance gets damaged. This situation arises as a result of some fault in the circuit and can b…