\( = \frac{{{{\left( {6.62 \times {{10}^{ - 34}}} \right)}^2}}}{{2 \times 9.1 \times {{10}^{ - 31}} \times {{\left( {7.5 \times {{10}^{ - 12}}} \right)}^2}}}\) \( \times \frac{1}{{1.6 \times {{10}^{ - 19}}}}{\text{eV}}\)
Alternate method
\(\lambda=\sqrt{\frac{150}{V}}\)
\(\Rightarrow \quad 7.5 \times 10^{-12}=\sqrt{\frac{150}{V}}\)
\(V=\frac{80}{3} \mathrm{kV}\)
Energy \(=\frac{80}{3} \mathrm{keV}=25 \mathrm{keV}\)
[$1 eV=1.6\times 10^{-19}\,J$ આપેલ છે.]