Chapter 24, Problem 65GP

(a)

To determine

The wavelength and frequency of the $H_{\alpha }$ line of hydrogen gas in a laboratory in which the discharge tube produces first-order bright band at a distance of 17.4 cm from the central maxima if a grating spectrograph has 5000 lines/cm and is placed by a distance of $0.500\text{ m}$ from the film.

(b)

To determine

The wavelength and frequency of the $H_{\alpha }$ line coming from the galaxy in a cluster. Hydra A produces first-order bright band at a distance of 18.4 cm from the central maxima if the grating spectrograph has 5000 lines/cm and is placed at 0.500 m from the thin film.

(c)

To determine

The possible reason for the frequency differences of $H_{\alpha }$ line from the galaxy and $H_{\alpha }$ line from the lab source if the grating spectrograph has 5000 lines/cm and is placed at a distance of 0.500 m from the thin film.