The series in the he spectrum that corresponds to the set of transitions where the electron falls from a higher level to the nf = 4 state is called the pickering series, an important series in solar astronomy. calculate the pickering series wavelength associated with the excited state ni = 6.

Refrigerant-134a flows through a carnot heat pump cycle at 0.5 kg/s. it is known that the maximum absolute temperature in the cycle is 1.1 times the minimum absolute temperature, and the net power input to the cycle is 2.5 kw. if the refrigerant changes from a saturated vapor to a saturated liquid during the heat rejection process, determine the maximum magnitude of the enthalpy of vaporization for this process in kj/kg (with 3 significant figures).