A reversible refrigerator operates between a low temperature reservoir at TL and a high temperature reservoir at TH . Its coefficient of performance is given by

The short distance from the objective lens to the object causes problems at high magnification. which of the following is the most serious? a. cleaning the object surface b. positioning the object c. reflection from the object surface. d. illumination of the object

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)?

Air is flows through an adiabatic nozzle with an inlet pressure of 400 psia at a temperature of 300°f and a velocity of 20 ft/s. the outlet pressure is 40 psia and the velocity is 800 ftl/s. determine the outlet temperature of the air using: a) property tables b) specific heat (using the specific heat value for air at 300°f)