Same as law of conservation of energy. Fluid: material that flows, i.e. liquids, gases, and plasmas. Focal length: distance from the focal point to the center of a lens or vertex of a mirror. Focal point: location at which rays parallel to the optical axis of an ideal mirror or lens converge to a point. Forbidden gap: energy values that electrons in a semiconductor or insulator may not have. Force: agent that results in accelerating or deforming an object. Frame of reference: coordinate system used to define motion.
Tuberculosis skin test facts. 1  The tuberculosis skin test is also known as the tuberculin test or PPD test.  The PPD test is used to determine if someone has developed an immune response to the bacterium that causes tuberculosis (TB).
A tuberculosis test, also known as a TB test, is a skin test that determines if someone has developed an immune response to a bacteria that causes tuberculosis. TB is a common disease that kills more than 3 million people worldwide each year. A visit to your family doctor can see prices ranging anywhere from $75 to as much as $300. 2  Those with health insurance may find the insurance company covers most if not all of the test is. 3  Check with your local health insurance provider to see what is covered.