Telephone Bells - The old Type

Where a bell is powered by AC a different design, the polarised bell, may be used. These have an armature containing a permanent magnet, so that this is alternately attracted and repelled by each half-phase and different polarity of the supply. In practice, the armature is arranged symmetrically with two poles of opposite polarity facing each end of the coil, so that each may be attracted in turn. No contact breaker is required, so the bells...

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Electric Bell

An Electric bell works on the idea of Electromagnetism. Working: The bell or gong (B), which is often in the shape of a cup or half-sphere, is struck by a spring-loaded arm with a metal ball on the end called a clapper (A), actuated by an electromagnet (E). In its rest position the clapper is held away from the bell a short distance by its springy arm. When an electric current is passed through the winding...

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Electromagnetism

History of the Electromagnetic Theory: Electricity and Magnetism which were once thought of two different types of interactions but was changed when scientists, especially Maxwell observed that there were a few things common between Electricity and Magnetism. These were: James Clerk Maxwell Electric charges attract or repel one another with a force inversely proportional to the square of the distance between them: unlike charges attract, like...

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Electric Field and the concept of Electromagnetism

Micheal Faraday first introduced the idea of electric fields and electromagnetism. He to coil of copper and attached an Ammeter to it. Then he put a magnet thorough the coil and observed a flow of electricity. The he pulled the magnet out and observed that there was no electricity. An electric field surrounds electrically charged particles and time-varying magnetic fields. The electric field depicts the force exerted...

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Electricity

Electricity is the flow of electrons form one place to another. It is also the flow of electric charge. Charge or Electric charge: It is something a man can never define explain and may not also in the future. But it is only understood as a concept. Electric charge is a property of certain subatomic particles, which gives rise to and interacts with the electromagnetic force, one of the four fundamental forces of nature....

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Simple Harmonic Motion

Simple Harmonic Motion(SHM) is a type of oscillatory motion. It is where restoring force is directly proportional to the displacement. The motion of a simple pendulum as well as molecular vibration are examples of SHM.  Simple Pendulum executing SHM A simple harmonic oscillator is attached to the spring, and the other end of the spring is connected to a rigid support such as a wall. If the system...

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Oscillations

When a simple pendulum is pushed through a small distance and observed, we find that the pendulum keeps moving to and fro about its initial position. It moves through its initial position, moves the farthest from there to a maximum height and stops for a few milliseconds(observable) and moves again through its initial position to the other end of the same height(without friction). Thus we can describe the pendulum to be oscillating about...

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Uses of gravity

Gravitational force is needed a lot. We depend on gravity for many things. We are able to stand on the Earth's surface only because of gravity. The Gravitational force keeps us bound to the Earth's surface and does not let us escape to vacuum though rockets have enough power to do so. Gravity varies from place to place. The fluids in our body are right in their places because gravity holds them. The muscles in our body can be made stronger only because of gravity. The Sun, Moon, Earth and celestial objects are in the orbits only because of gravity. The...

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Gravitational Energy

Gravitation, or gravity, is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass and causes them to fall to the ground when dropped. Gravitation causes dispersed matter to coalesce, and coalesced matter to remain intact, thus accounting for the existence of the Earth,...

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Friction

Friction is a resisting force which opposes the movement or relative motion of two surfaces in contact with each other. Friction does not let two bodies slide easily. There are several types of friction Dry Friction: Friction that exists between two solid surfaces in contact. Fluid friction or viscosity: Friction that exists between layers of a viscous fluid. Skin friction: A force which opposes the movement of a solid through a fluid. Internal...

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