Can a transformer step up power?

Answer 1

It is a basic tenet of physics that, in a closed system, energy can neither be created nor destroyed. Energy can, however, be transformed. It follows from this that the power output from a system cannot exceed the power input. Therefore, in a transformer, the primary power and the secondary power are always equal (at least in theory). A transformer can step voltage up or step it down. Since power equals voltage multiplied by current then, if the transformer secondary voltage is stepped up, the current must be stepped down by the same factor (that is, if the voltage is stepped up by a factor of 4 then the current is stepped down by a factor of 4). Any increase in voltage in the secondary of a transformer will result in a corresponding inversely proportional decrease in secondary current. From a practical standpoint, secondary power is always somewhat less than primary power due to resistive losses in the transformer windings as well as eddy current and hysteresis losses (magnetic losses) in the transformer core. These losses produce heat which compounds the transformer inefficiency. The primary and secondary windings are made from copper and, like all metals, it has a positive temperature coefficient of resistance. This is a fancy way of saying that when the copper windings of a transformer get hotter their electrical resistance goes up which further increases the resistive losses in the transformer.

Answer 2

in a step- up transformer the primary consists of a small number of turns of thick copper wire and the secondary consists of a large number of turns of thin copper wire. the no. of turns in the primary is less than the no. of turns in secondary

Answer 3

Step up voltage to reduce energy loss from the cables that make up the national grid. The lower the voltage the more energy lost.

Answer

A 'step-up' transformer is any transformer whose secondary voltage is greater than its primary voltage.