Engineering, 20.09.2019 22:30 vitanoeymailcom705
Alight-emitting diode (led) is a component that produces light. when an led has current running through it, we sometimes make the rough approximation that the voltage across the led is constant regardless of how much forward current is flowing through it (within a certain range of current). this approximately constant voltage is given the designation vf. led data sheets specify the current to be used through the device when lighting it; this current is given the designation if. choose a resistor r1 (specify a resistance and power rating as your answer) to be used in the following circuit to illuminate a red led with a vs = 6 v battery. this red led has if = 20 ma and vf = 1.4 v. use the smallest power rating possible for the resistor; you have the following resistor power ratings available: 1/16 w, 1/8 w, 1/4 w, 1/2 w, and 1w. the actual power dissipated by the resistor should not exceed the power rating of the resistor you choose. (you do not need to choose a standard resistance value for the resistor.)
Answers: 2
Engineering, 03.07.2019 14:10, BardiFan
Amass of m 1.5 kg of steam is contained in a closed rigid container. initially the pressure and temperature of the steam are: p 1.5 mpa and t 240°c (superheated state), respectively. then the temperature drops to t2= 100°c as the result of heat transfer to the surroundings. determine: a) quality of the steam at the end of the process, b) heat transfer with the surroundings. for: p1.5 mpa and t 240°c: enthalpy of superheated vapour is 2900 kj/kg, specific volume of superheated vapour is 0. 1483 m/kg, while for t 100°c: enthalpy of saturated liquid water is 419kj/kg, specific volume of saturated liquid water is 0.001043m/kg, enthalpy of saturated vapour is 2676 kj/kg, specific volume of saturated vapour is 1.672 m/kg and pressure is 0.1 mpa.
Answers: 3
Engineering, 04.07.2019 18:10, tjeffers90028
Refrigerant 134a enters an insulated compressor operating at steady state as saturated vapor at -26°c with a volumetric flow rate of 0.18 m3/s. refrigerant exits at 9 bar, 70°c. changes in kinetic and potential energy from inlet to exit can be ignored. determine the volumetric flow rate at the exit, in m3/s, and the compressor power, in kw.
Answers: 1
Engineering, 04.07.2019 18:10, ayoismeisjjjjuan
Manometers are good examples of measuring instruments, nowadays they are not as common as before. a)-capacitive probe gauges b)-gravitational gauges deformation ) gauges d)-digital gauges
Answers: 1
Alight-emitting diode (led) is a component that produces light. when an led has current running thro...
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