Suppose that a radio station broadcasts simultaneously from two transmitting antennas at two different locations. compared with only one transmitting antenna, the reception with two transmitting antennas (a) is always better (b) is always worse (c) can be either better or worse, depending on the distance traveled by each wave.
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Physics, 21.06.2019 22:00
Aroll in a paper machine is powered by a separately excited dc machine. operating point 1 (under load): the roll typically operates at 764 rpm and must provide 301 nm of torque to oppose the load of the paper. the armature voltage is 230v for this operating point operating point 2 (no load): when the load is removed the speed of the roll increases to 900 rpm (the field characteristics are unchanged) la ea dev m (a) calculate the maximum torque (units of nm) that the motor can supply with this applied voltage (b) calculate the value of the armature resistance, ra (in ohms) (c) at operating point 1 (loaded condition), the field current, i, and the total input power (armature field), are measured to be to be 10 a and 28,600 w respectively. use this information to calculate the value of the field resistance, rf (in ohms). (d) (d) at operating point 1 (loaded condition), calculate the motor efficiency. express your answer as a percent to at least 2 significant digits. (d) if the field voltage is reduced by 1/2, calculate the new stall torque (in nm) of the motor (f). if the field voltage is reduced by 1/2, calculate the new no-load speed (in rad/sec)
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Physics, 22.06.2019 02:30
Agas contained within a piston-cylinder assembly undergoes three processes in series: process 1ď 2: compression with pv= constant from 1 bar and 1 liter to 4 bar. process 2ď 3: constant pressure expansion to 1 liter. process 3ď 1: constant volume calculate the pressure and volume at each state, and sketch the processes on a p-vdiagram labeled with pressure and volume values at each numbered stat
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Physics, 22.06.2019 02:50
Ammonia enters the expansion valve of a refrigeration system at a pressure of 10 bar and a temperature of 18oc and exits at 6.0 bar. the refrigerant undergoes a throttling process. determine the temperature, in oc, and the quality of the refrigerant at the exit of the expansion valve.
Answers: 3
Physics, 22.06.2019 08:00
What is the average speed of a car that travels 40 mph for 1 hour and 60 mph in another hour?
Answers: 1
Suppose that a radio station broadcasts simultaneously from two transmitting antennas at two differe...
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