Sometimes this reactivity of your airways after an infection is the first sign you have asthma. The bit of blood may be a little blood vessel trauma from forceful coughing. It is time to see your doctor for an evaluation. Hope this helps; take care:) ...Read more.
A solenoid is a type of electromagnet when the purpose is to generate a controlled magnetic field.If the purpose of the solenoid is instead to impede changes in the electric current, a solenoid can be more specifically classified as an inductor rather than an electromagnet. solenoid is a type of electromagnet when the purpose is to generate a controlled magnetic field.
Also see toroid. A solenoid is a coil of insulated or enameled wire wound on a rod-shaped form made of solid iron, solid steel, or powdered iron.Devices of this kind can be used as electromagnets, as inductors in electronic circuits, and as miniature wireless receiving antennas.n a solenoid, the core material is ferromagnetic, meaning that it concentrates magnetic lines of flux. This increases the inductance of the coil far beyond the inductance obtainable with an air-core coil of the same dimensions and the same number of turns.