\(N_{p} = 3000 turns\)
\(N_{s} = 500 turns\)
\(E_{p} = 240V_{r.m.s}\)
\(E_{s} = ?\)
\(\frac{N_{s}}{N_{p}} = \frac{E_{s}}{E_{p}}\)
\(\frac{500}{3000} = \frac{E_{s}}{240}\)
\(\implies E_{s} = \frac{240\times500}{3000} = 40V\)