Part of the energy is lost in heat by processes in the transformer. That is usually only 1-2% for power supply Transformers. The remainder is passed on to the load.
There is no selective device to determine the amount of voltage. A transformer is selected by the voltage available at the site for the primary and the load on the secondary side of the transformer.
A transformer in standby mode typically consumes a small amount of electricity, known as "no-load loss" or "core loss," which is primarily due to the magnetization of the core. This loss is generally low, often ranging from 1 to 5 watts for smaller transformers. The exact amount can vary based on the transformer's design and efficiency. Overall, while the power consumption is minimal, it can accumulate over time if the transformer remains in standby for extended periods.
The result is that the transformer runs cool and contented. The '250 KVA' rating on the transformer is its maximum ability to transfer power from its input to its output without overheating, NOT an amount of power always running through it. If the 3 KVA load happens to be the only thing connected to the transformer at the time, then only 3 KVA flows into the transformer from the primary line, and only 3 KVA leaves the transformer secondary.
increase the amount of voltage
When light hits clear glass, some of it is transmitted through the glass, some is reflected off the surface, and a small amount is absorbed by the glass. The amount of light that is transmitted or reflected depends on the angle of incidence and the refractive index of the glass.
When light falls on a window glass, some of it is reflected back, some is absorbed by the glass, and some is transmitted through the glass. The amount of light that is reflected, absorbed, and transmitted depends on the angle of incidence, the type of glass, and the properties of the light.
The correct symbol for kilovolt amperes is 'kV.A, not kva. A volt ampere is the product of the transformer's secondary rated voltage and its rated current. It is not rated in watts, because the transformer designer has no idea what sort of load is to be applied to the transformer, and it is the load that determines the amount of watts, not the transformer.
Rephrase your question so that it makes sense.
bandwidth
well the working of the step doen transformer depends on the number of turns on the secondary side of the transformer, now in the case of a step down transformer, the number of turns in the secondary windings are less as compared to the number of turns at the primary side/winding, so the amount of flux which links the secondary side of the transformer is also less resulting in the production of less amount of emf at the secondary side. hence the status of the voltage is decreased as compared to the voltage of the primary side.
well the working of the step doen transformer depends on the number of turns on the secondary side of the transformer, now in the case of a step down transformer, the number of turns in the secondary windings are less as compared to the number of turns at the primary side/winding, so the amount of flux which links the secondary side of the transformer is also less resulting in the production of less amount of emf at the secondary side. hence the status of the voltage is decreased as compared to the voltage of the primary side.
When a large amount of solvent is added to a concentrated solution, the concentration of the solution decreases. This process is known as dilution. The overall volume of the solution increases, but the amount of solute remains the same.