What is a variable speed drive? A variable speed drive is a piece of equipment that regulates the speed and rotational force, or torque output, of an electric motor. The background and technology. There are millions of motors in use in industry and offices around the world.
The specific gravity for Obsidian is 2.35, it's refractive index is 1.48-1.51, and it's double refraction is None. History Obsidian is named after a Roman, Obsius.
6 MISCELLANEOUS PROPERTIES SPECIFIC GRAVITY The specific gravity of most minerals varies between 2.5 and 3, and is dependent upon both the atomic weight of its constituent atoms, and how closely packed they are. In hand-sample, one can quickly determine if a sample has low, moderate or high density.