\(\frac{ V _{2}}{ V _{1}}=\frac{ N _{2}}{ N _{1}}\)
Substitute the values as,
\(\frac{V_{2}}{120}=\frac{1}{50}\)
\(V _{2}=\frac{12}{5}\)
Let transformer is ideal.
\(P _{ in }= P _{\text {out }}\)
Therefore,
\(P _{\text {out }}=\frac{ V _{2}^{2}}{ R _{2}}\)
Substitute the values as,
\(P_{\text {out }}=\frac{(12 / 5)^{2}}{10}\)
\(=5.76 W\)