Answer:
3.18 V
Explanation:
RMS voltage of a generator is given by:
[tex]V_{rms}=\frac{1}{\sqrt 2}V_o[/tex]
Given:
Output voltage at t =0.01 s is 4.2 V
[tex]V = V_o sin (120t)\\ 4.2 = V_o sin (120 \times 0.01) \\ V_o = 4.5 V [/tex]
[tex]V_{rms}=\frac{1}{\sqrt 2}4.5 V = 3.18 V[/tex]