NEIEP Mechanics Practice Exam

What happens to the output voltage if the turns ratio of a transformer is increased?

1. The output voltage increases

2. The output voltage decreases

3. The output voltage remains the same

4. The output voltage becomes negative

The correct answer is: The output voltage increases

In a transformer, the output voltage is directly related to the turns ratio, which is the ratio of the number of turns on the primary winding to the number of turns on the secondary winding. When the turns ratio is increased, this means that there are more turns on the secondary winding compared to the primary winding. According to the transformer basic principle, the output voltage is determined by the formula: \[ V_{s} = V_{p} \times \left(\frac{N_{s}}{N_{p}}\right) \] Where \( V_{s} \) is the secondary (output) voltage, \( V_{p} \) is the primary (input) voltage, \( N_{s} \) is the number of turns on the secondary coil, and \( N_{p} \) is the number of turns on the primary coil. If the turns ratio (i.e., \( \frac{N_{s}}{N_{p}} \)) increases, this results in a proportionally higher output voltage for a given input voltage. Therefore, in the scenario where the turns ratio is increased, the output voltage indeed increases, aligning with the foundational principles of transformer operation. This is why the correct answer is that