The phenomena of diffraction can be used to measure the wavelength of a color of light. Diffraction is defined as the spreading of a wave into a region behind an obstacle. Interference is the superposing of one wave on another. Interference can be constructive or destructive. Magnetism Like magnetic poles repel and unlike magnetic poles attract.
Magnetic fields run out from the north pole and enter a magnet's south pole.
Closed loops are formed by magnetic field lines. This chapter will review these basic properties of magnets. Electrostatics Static electricity is stationary electricity. Static electricity can be produced by friction between two surfaces that are in close contact. The basic Law of Electrostatics states that opposite charges attract and like charges repel.