What do you mean <span>It has been observed that certain species of insects which had not previously caused significant harm have become serious pests. the best explanation for this phenomenon is that the pesticide killed off predators which had previously held this species in check. a mutation occurred in the species. the pesticide increased the vigor of the species. was able to be used by the pest as an additional food source is also a reproductive for some insect species. </span><span />
The transformer is a static electric machine (because it contains no moving parts) belonging to the broader category of converters. In particular the transformer to convert the parameters of voltage (V symbol unit [V] volts) and current (symbols The unit [A] amperes) input than output, while maintaining constant the amount of power electrical (less the losses due to hysteresis and eddy currents). The transformer is a machine able to operate only in alternating current, because it exploits the principles of electromagnetism linked to variable flows. <span>The transformer has paramount importance in today's world: without it, the electricity transmission grids that connect power plants to millions of homes and industries could not function</span>