The instantaneous voltages at three terminals marked X,Y and Z are given by $$V_{X}= V_{0} \sin \omega t$$, $$V_{Y}= V_{0} \sin (\omega t+\frac{2\pi}{3})$$
and $$V_{Z}= V_{0} \sin (\omega t+\frac{4\pi}{3})$$. An ideal voltmeter is configured to read rms value of the potential difference between its terminals. It is connected between points X and Y and then between Y and Z The reading(s) of the voltmeter will be