\(\frac{\lambda^{\prime}}{\lambda}=1-\frac{v}{c}\)
\(=1-\frac{\lambda^{\prime}}{\lambda}=\frac{\lambda-\lambda^{\prime}}{\lambda}=\frac{\Delta \lambda}{\lambda}\)
Therefore \(\Delta \lambda=\lambda \times \frac{v}{c}\)
\(=5000 \mathring A \times \frac{1.5 \times 10^{6}}{3 \times 10^{8}}=25 \mathring A\)
(where \(\Delta \lambda\) is the change in the wavelength)