A diffraction grating with $d=2000nm$ is used with a mercury discharge tube. At what angle will the first$-$order blue$-$green wavelength of mercury appear? What other orders can be seen, and at what angle will they appear? Show your work.

The diffraction grating of Question $7$ is used at a distance $L=50\mathrm{.}0cm$ from the slit. What is the distance $D$ from the slit to the first$-$order image for the blue$-$green wavelength of mercury? Show your work.

What are the voltage and current of the spectrum tube power supply?