What is the output voltage of a step-up transformer?

• A. Equal to the input voltage
• B. Lower than the input voltage
• C. Higher than the input voltage
• D. Variable and depends on current conditions

Answer: (C)

In a step-up transformer, the primary purpose is to increase the voltage from the primary winding to the secondary winding. The design of this transformer includes a larger number of turns of wire in the secondary coil compared to the primary coil. According to the transformer equation, the voltage ratio between the primary and secondary windings is directly proportional to the ratio of the number of turns in each winding.

As such, since the secondary winding has more turns, the output voltage in the secondary coil is greater than the input voltage supplied to the primary coil. This behavior is inherent to the functioning of step-up transformers, which are commonly used in applications where higher voltage levels are required, for example, in power distribution systems to reduce energy losses over long distances.

The incorrect options fail to capture this fundamental principle of how step-up transformers operate: they do not maintain the input voltage nor lower it, nor do they provide a variable output depending on current conditions, as their output is determined by their turn ratio and the input voltage applied.