The relationship between the peak value and r.m.s value of electricity supply is given as

V\(_{r.m.s}\) = \(\frac{V_o}{\sqrt{2}}\)

where V_o = peak voltage

V_o = V\(_{r.m.s}\) x \(\sqrt{2}\)

= 240 x \(\sqrt{2}\)

= 339.5v

= 340v