If in a Y-connected ac generator, each phase voltage has a magnitude of 90 VRMS, what is the magnitude of each line voltage?

Solution (By Examveda Team)

Understanding Y-connected Generators:
Imagine a Y-connected generator as a three-legged star. Each leg represents a phase, and the voltage across each phase is called the phase voltage.

The line voltage, on the other hand, is the voltage measured between any two of the three legs (lines).

Calculating Line Voltage:
In a Y-connection, the line voltage is not simply equal to the phase voltage. Because the phases are 120 degrees apart, the relationship is based on the geometry of an equilateral triangle.

The formula to find the line voltage (V_L) from the phase voltage (V_ph) is: V_L = √3 * V_ph

Solving the Problem:
We are given that the phase voltage (V_ph) is 90 VRMS. Using the formula:
V_L = √3 * 90 V ≈ 156 V

Therefore, the magnitude of each line voltage is approximately 156 V.

The Correct Answer:
The correct option is C: 156 V