Electromagnetic waves, their types and characteristics

Electromagnetic Wave Electromagnetic Wave are waves composed of undulating electrical fields and magnetic fields. The different kinds of Electromagnetic Waves, such as Light and radio waves, form the electromagnetic spectrum. All electromagnetic waves have the same speed in a vacuum, a speed expressed by the letter c (the speed of light) and equal to about … Read more

Universal law of gravitation, gravity, acceleration due to gravity

Newton’s law of universal Gravitation states that a particle attracts every other particle in the universe using a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers. Gravitation Gravitation is the force by which every mass or particle of matter, including … Read more

Measurement of physical quantities and system of Units

Measurement of any physical quantity involves comparison with a certain basic, arbitrarily chosen, internationally accepted reference standard called unit. The result of a measurement of a physical quantity is expressed by a number (or numerical measure) accompanied by a unit. A unit of measurement is a definite magnitude of a quantity, defined and adopted by … Read more

Force and laws of motion

Motion Motion is a change in position of an object with respect to time. Motion is typically described in terms of displacement, distance, velocity, acceleration, time and speed. The branch of physics which deals with the study of motion of material objects is called mechanics. Mechanics is divided into following branches. (i) Statics : Statics … Read more

Conductors, semiconductors and insulators

Conductors, semiconductors and insulators Materials are classified as conductors, insulators, or semiconductors according to their electric conductivity. The classifications can be understood in atomic terms. Electrons in an atom can have only certain well-defined energies, and, depending on their energies, the electrons are said to occupy particular energy levels. In a typical atom with many … Read more

Introduction to solar appliances viz Solar cell, solar cooker, water heater etc.

Sunlight is Earth’s most abundant energy source and is delivered free of charge. Indeed, the energy from sunlight reaching the land surface of the earth  is thousands of times greater than the world’s current total annual consumption of energy. Yet harnessing sunlight’s energy content directly—rather than indirectly in fossil fuels, wind, or hydroelectric power—makes only a small contribution to humanity’s energy … Read more

Holography

  Holography Holography, means of creating a unique photographic image without the use of a lens. The photographic recording of the image is called a hologram, which appears to be an unrecognizable pattern of stripes and whorls but which—when illuminated by coherent Light, as by a laser beam—organizes the light into a three-dimensional representation of … Read more

Linear motion, circular motion and vibrational motion

Linear motion Linear motion, also called uniform motion or rectilinear motion, motion in one spatial dimension.  According to Newton’s first law (also known as the principle of inertia), a body with no net force acting on it will either remain at rest or continue to move with uniform speed in a straight line, according to … Read more