The network shown in the
figure represents a simple power transmission system.
The generator produces 60 Hz and is modeled by a simple Thévenin equivalent.The transmission line consists of a long length of copper wire and can be accurately described as a 50Ω resistor.
Determine the load current
and the average power the generator must produce so that the load receives 1,000 watts of average power.
Why does the generator need to generate more than 1,000 watts of average power to meet this requirement?
Suppose the load is changed to that shown in the second
figure .
Now how much power must the generator produce to meet the same power requirement?Why is it more than it had to produce to meet the requirement for the resistive load?
The load can be
compensated to have a unity
power factor (see
exercise ) so that the voltage and current are in phase for maximum power efficiency.
The compensation technique is to place a circuit in parallel to the load circuit. What element works and what is its value?
With this compensated circuit, how much power must the generator produce to deliver 1,000 average power to the load?
Simple power transmission system
Modified load circuit
Optimal power transmission
The following
figure shows a general model for power transmission.
The power generator is represented by a Thévinin equivalent and the load by a simple impedance.In most applications, the source components are fixed while there is some latitude in choosing the load.
Suppose we wanted the maximize "voltage transmission:"
make the voltage across the load as large as possible.What choice of load impedance creates the largest load voltage?
What is the largest load voltage?
If we wanted the maximum current to pass through the load, what would we choose the load impedance to be?
What is this largest current?
What choice for the load impedance maximizes the average power dissipated in the load?
What is most power the generator can deliver?
One way to maximize a function of a complex variable is to write the expression in terms of the variable's real and imaginary parts, evaluate derivatives with respect to each, set both derivatives to zero and solve the two equations simultaneously.
Big is beautiful
Sammy wants to choose speakers that produce very loud music.
He has an amplifier and notices that the speaker terminals are labeled"
source."
What does this mean in terms of the amplifier's equivalent circuit?
Any speaker Sammy attaches to the terminals can be well-modeled as a resistor.
Choosing a speaker amounts to choosing the values for the resistor.What choice would maximize the voltage across the speakers?
Sammy decides that maximizing the power delivered to the speaker might be a better choice.
What values for the speaker resistor should be chosen to maximize the power delivered to the speaker?
Sharing a channel
Two transmitter-receiver pairs want to share the same
digital communications channel. The transmitter signalswill be added together by the channel. Receiver design
is greatly simplified if first we remove the unwantedtransmission (as much as possible). Each transmitter
signal has the form
where the amplitude is either zero or
and each transmitter uses its own frequency
.
Each frequency is harmonically related to the bitinterval duration
,
where the transmitter 1 uses the the frequency
.
The datarate is 10Mbps.
Draw a block diagram that expresses this
communication scenario.
Find circuits that the receivers could employ to
separate unwanted transmissions. Assume the receivedsignal is a voltage and the output is to be a
voltage as well.
Find the second transmitter's frequency so that the
receivers can suppress the unwanted transmission byat least a factor of ten.
Questions & Answers
Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you.
Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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