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

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

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

Electric current

Current Electricity Electric current is the rate of flow of electric charge through a conducting medium with respect to time. It is caused by drift of free electrons through a conductor to a particular direction.Charges in motion constitute an electric current. Such currents occur naturally in many situations. Lightning is one such phenomenon in which … Read more