A Si pin photodiode has an active light-receiving area of diameter 0.4 mm. When radiation of wavelength 700 nm (red light and intensity 0.1 mW cm^-2 is incident it generates a photocurrent of 56.6 nA. What is the responsivity (A W^-1) and quantum efficiency (QE) of the photodiode at 700 nm?

An external consultant recommends that a plant installs a bank of capacitors for power factor correction. this will reduce the peak electrical demand charges by an average of 93 kw every month. the plant current pays $13 per kw in peak demand charges. the capacitor bank will include 223 kw of fixed capacitors, and 183 of variable capacitors. the fixed capacitors cost $59 per kw, and the variable capacitors will cost $65 per kw. the consultant charges 21% of the equipment costs to install the capacitors. because this project will reduce the demand for the electric utility, they are prepared to provide a one-time rebate of $42 per kw of reduced demand. what is the simple payback period for this project (in years)?