# Student Essay

342 Words2 Pages
Magnetism What is Magnetism? by Numan Sajid Magnetism is a force of attraction or repulsion that acts at a distance. It is due to a magnetic field, which is caused by moving electrically charged particles. It is also inherent in magnetic objects such as a magnet. What is a magnetic field? A magnetic field consists of imaginary lines of flux coming from moving or spinning electrically charged particles. Examples include the spin of a proton and the motion of electrons through a wire in an electric circuit. Magnetic force Magnetic fields exert a force on particles in the field, called the Lorentz force. The motion of electrically charged particles gives rise to magnetism. The magnetic force acting on a single electric charge depends on the size of the charge, its speed, and the strengths of the electric and magnetic fields. Attraction When two magnets or magnetic objects are close to each other, there is a force that attracts the poles together. Force attracts N to S Magnets also strongly attract ferromagnetic materials such as iron, nickel and cobalt. Repulsion When two magnetic objects have like poles facing each other, the magnetic force pushes them apart. Force pushes magnetic objects apart Electric charges and magnetism similar Just as the positive (+) and negative (−) electrical charges attract each other, the N and S poles of a magnet attract each other. In electricity like charges repel, and in magnetism like poles repel. Electric charges and magnetism differ The magnetic field is a dipole field. That means that every magnet must have two poles. On the other hand, a positive (+) or negative (−) electrical charge can stand alone. Electrical charges are called monopoles, since they can exist without the opposite charge. An Activity http://www.harcourtschool.com/activity/electromagnets/ Summary Magnetism is a force