Question

An ac generator has a maximum output emf of 215 V. What is the rms potential difference?

Answer 1

The rms potential difference of an ac generator is given by:
$V_{rms} = \frac{V_0}{ \sqrt{2} }$
where $V_0$ is the maximum value of the voltage.

For the ac generator in our problem, $V_0=215 V$, therefore the rms value of the potential difference is
$V_{rms} = \frac{V_0}{ \sqrt{2} } = \frac{215 V}{ \sqrt{2} }=152 V$