You might be most familiar with sonography's role in the field of obstetrics to produce an ultrasound image of an unborn baby. Sonography is also used to analyze tissues and organs of the body, such as the heart, eyes and abdomen.
Etymology: Pierre S. de Laplace, French physicist, 1749-1827. a principle of physics that the tension on the wall of a sphere is the product of the pressure times the radius of the chamber and the tension is inversely related to the thickness of the wall.
Lenz Law is a way to find the direction of induced current in a conducting loop. As per Faraday's Law of electromagnetic induction, a current is induced in a conducting loop by the changing magnetic flux. This induced current itself produces a magnetic field and hence a magnetic flux.