Let tpwm be 1 second. a) if tpwm is divided into 500 intervals, what is the length of each interval? b) if tpwm is divided into 500 intervals, what is the duty cycle resolution? c) say that vtrue is 4 v and vfalse is 0 v. if tpwm is divided into 10 intervals, and the desired output voltage is 2 v, how close can you get using pwm? d) say that vtrue is 4 v and vfalse is 0 v. if tpwm is divided into 10 intervals, and the desired output voltage is 3.25 v, how close can you get using pwm? e) say that you are given some tpwm and some number of intervals n to specify ton. if tpwm doubles, what happens to the size of the smallest possible ton? what happens to the duty cycle resolution?

Tech a says never use a water hose to clean up dust after a repair. tech b says never use a floor scrubber to clean up dust after repairs. who is correct?

Consider a power plant with water as the working fluid that operates on an ideal rankine cycle. it has a net power output of 45mw. superheated steam enters the turbine at 7mpa and 500°c (h=3411.4 kj/kg; s=6.8 kj/kg k) and is cooled in the condenser at a pressure of 10 kpa by running cooling water from a lake through the tubes of the condenser at a rate of 2000 kg/s. (a) show the cycle on a t-s diagram (a right schematic is fine - you do not need to calculate the temperatures at each point); (b)-determine the work done by the turbine and the pump in kj/kg; (c)-the mass flow rate of water used by the power plant; (d)-the thermal efficiency of the cycle; (e)-the temperature rise of the cooling water. assume the cooling water is incompressible with cp 4.18 kj/kg°c.

Ir at sea level and 30°c and 50% relative humidity flows at a rate of 1 kg/s through a cooling coil that has an apparatus dewpoint of 10°c. the air leaves the coil at 15°c. determine the following: 3.1)- relative humidity of the air leaving the coil; 3.2)- moisture content of the air leaving the coil; 3.3)- sensible heat factor; 3.4)- total heat transfer rate; 3.5)- sensible heat transfer rate 3.6)- latent heat transfer rate