Physics

Electricity and Circuit – Electricity Conductors and Insulators * Materials that allow electricity to pass through them are called conductors. * Materials that do not allow electricity to pass through there are called insulators. * We need conducting materials to make electrical circuits. * Air is an insulator * All electrical appliances are covered with ... Read more

Sound - Production and Propagation of Sound * Sound is form of energy that produces the sensation of hearing in our ears. * Sound is produced due to the vibration of objects. * Intensity of sound is the amount of sound energy incident per unit time per unit area. * Sound propagates through a medium. ... Read more

Reflection of Light * Light travels in straight lines. * A shiny or polished surface, such as a mirror, can change the direction of incident light. * The bouncing of light by any smooth surface like a mirror, back into the same medium, is called reflection of light. * The likeness of light by an ... Read more

Heat – Transfer of Heat * Heat flows from a hotter object to a colder object. * He heat flows a hot body is gradually transferred the particles of the surrounding air that are comparatively cooler. * The process by which heat is transferred from the hotter part to the colder part of an object, ... Read more

Pressure * Pressure is the amount of force acting on a unit surface area. * Pressure is calculated by dividing force with area. * Like solids, all fluids exert pressure. * Matter that has a tendency to flow is termed as a fluid. * Dams can break down due to the force that is caused ... Read more

Universal Law of Gravitation * The force of attraction between any two bodies applies to all the bodies in the universe. * The moon revolving around the earth is under the action of centripetal force. The magnitude of gravitational force varies with the:   *  Distance of the object from the earth   *  Mass ... Read more

Motion and Measurement of Distance - Rest and Motion * A body is said to be at rest when it remains in its position for a long time (there is no change in its position). * A body is said to be in motion if it is changing its position with respect to its surrounding ... Read more

Motion and Time - Time and Speed * An object that covers less distance in a given time is said to be moving slow. * The one that covers more distance in the same time is said to be moving fast. * Speed is the distance covered by an object in unit time. * An ... Read more