explain why no spectrum is observed if the angle theta is zero why if the telescope is in line with the grating and slit what is observed in this position
Answers
Explanation:
CAUTION: The high voltage power supplies for the spectrum tubes used in this experiment contain connections across which there is a potential difference of 5000 volts. The possibility of a serious shock exists if these connections are touched. Be careful when adjusting the spectrum tubes or the power supplies.
PURPOSE:
In this experiment you will study the operation of a diffraction grating spectrometer. After calibrating the instrument you will measure the wavelengths of the first four lines of the Balmer series of hydrogen and compare your results to the predictions of Bohr model.
WHAT'S THE POINT?
To see how one can measure, quantitatively, the wavelength of a beam of light, using a simple instrument on a table top.
BACKGROUND READING:
Bohr model of the atom: C&J 30.3
Line spectra: C&J 30.2
Diffraction: C&J 17.2, 17.3, 27.5, 27.7. See Figures 27.37 and 27.38
APPARATUS:
The essential parts of the spectrometer are shown in Figure 1.
A sketch of a spectrometer showing the various adjustments A; Screws to level or align the telescope B; Knob to fix the position of the telescope. This knob must always be loosened before moving the telescope by hand and locked only to make fine adjustments with knob C. C, Fine adjustment knob. S, Screws to level or raise the prism table. E, Knob to fix the position of the graduated disc and prism table. When readings are taken with the telescope, this knob must be in the locked position. F, Screws to align the collimator. G, Knob for adjusting the slit width. The slit should be wide enough to allow a sufficient amount of light to pass through but as narrow as possible to allow accurate measurement.