Reference no: EM13711546
1. A d.c. to d.c. chopper circuit has the parameters of a source frequenCy of 150 Hz and an on time of 3 ms. vohage of 90 V, chopper When this chopper drives an inductive load of 1.5 0 and 15 mH, determine:
a. the average load current,
b. the maximum load current,
c. the minimum load current.
The same chopper circuit with the same parameters is then used to drive a d.c. series motor which has the following motor parameters:
field resistance Ft, = 0.08 0
armature resistance R. = 0.06 0
d.c. series motor constant k = 0.01
With an average armature current of 85 A, find:
d. the motor speed (in rpm),
e. the motor torque.
Streams of cold and warm air are mixed to get air
: In air-conditioning systems, streams of cold and warm air are mixed to get air with the right temperature. Consider a mixing chamber into which cold air enters at 8 degree C and 100 kPa at a rate of 0.55 m3/s and warm air enters at 30 degree C and 10..
|
Find the sum upto n terms
: find the sum upto n terms of the following sequence 3+33+333+... n terms
|
Determine the voltage of the source
: A piston-cylinder device contains 12 kg of saturated R-134a vapor at 3.2 bar. An electric source supplies 8 A current to a resistor within the cylinder for 4 minutes and there is heat transfer of 400 kJ to the system. During these energy interactions..
|
Draw a hierarchy chart and then plan the logic for a program
: Draw a hierarchy chart and then plan the logic for a program for the sales manager of The Couch Potato Furniture Company. The manager needs a program to determine the profit on any item sold. Input includes the wholesale price and retail price for..
|
Determine the average load current
: Chopper circuit has the parameters of a source frequenCy of 150 Hz and an on time of 3 ms. vohage of 90 V, chopper When this chopper drives an inductive load of 1.5 0 and 15 mH, determine the average load current.
|
Maximum shear stress can be adequately approximated
: The maximum torque produced by the engine of the car occurs at 4750 rpm, when the engine is generating 286 HP. The designer followed the following method and chosen steel shaft having yiled stress at 80,000 psi and a factor of safety = 4.
|
What is the gauge pressure in the container
: A rigid adiabatic container in a room with a barometric pressure of 100 kPa is divided into two unequal volumes as shown. V1 = 0.108 m3 and contains air (R = 0.2870 kJ/kg-K, k = 1.40) at a gauge pressure of 32 kPa and temperature of -3°C.
|
What rate is heat rejected from this engine as waste heat
: An engine burns 200 cubic feet per hour of natural gas with a heating value of 1000 btu/cubic feet. The engine produces 39.1 horsepower for this test. What is the average efficiency for this test? At what rate (btu/h) is heat rejected from this engin..
|
Shell-and-tube heat exchanger is used to cool flow of steam
: A shell-and-tube heat exchanger is used to cool a flow of steam using a stream of cooling water. The steam enters the heat exchanger at 0.1 bar and a quality of 91% (state 1), and exits as a saturated liquid at the same pressure (state 2). The mass f..
|