Electricity and Magnetism

Electricity and Magnetism

It is a phenomenon associated with stationary or moving electric charges. Electric charge is a fundamental property of matter and is borne by elementary particles. In electricity the particle involved is the electron, which carries a charge, as negative. Electricity is not a form of energy. Instead, it is said that an electric current is a flow of “electricity”.

Coulomb’s Law

Static electricity is an electric phenomenon in which charged particles are transferred from one body to another.

For example, if two objects are rubbed together, especially if the objects are insulators and the surrounding air is dry, the objects acquire equal and opposite charges and an attractive force develops between them.The object that loses electrons becomes positively charged, and the other becomes negatively charged.

When one object is rubbed against another, static electricity is created. This is because the rubbing creates a negative charge that is carried by electrons. These electrons build up to produce static electricity.

Some other examples are – 

• Rubbing one’s feet on the carpet
• Clothes tumbling in the dryer

We call one end of the magnet the North (N) Pole and the other end the South (S) Pole.

The force of the magnetic field flows from the North Pole to the South  Pole. If you hold two magnets close to each other you would find that if you try to push the two North poles (N) or the two South poles (S) together, they repel each other. If you put the North Pole (N) near the South Pole(S), they attract each other.

Like poles repel, unlike poles attract.

When current flows through any wire it creates a magnetic field around the wire as it goes along. Generally it’s quite weak because a single wire is not strong enough to pickup metal objects. Here “I”Is the current and “B” is the magnetic field.

Electrostatics, the study of electric charges at rest, was initially found by the ancient Romans who observed how a comb after brushing would attract particles. It is known that electric charges are in two different forms, positive charges and negative charges. Like charges repel each other, and differing charges attract.

The force that attract positive charges to negative charges weakens with distance, but is very strong — up to 40 times stronger than the pull of gravity at the surface of the earth. This fact can easily be described by a small magnet that can hold or suspend an object. The small magnet exerts a force at least equal to the gravitational from the entire Earth.