The
rms (root-mean-square) value of
a periodic signal is defined to be
where
is defined to be the signal's
period :
the smallest positive number such that
.
What is the period of
?
What is the rms value of this signal? How is it
related to the peak value?
What is the period and rms value of the
depictedsquare wave , generically denoted
by
?
By inspecting any device you plug into a wall socket,
you'll see that it is labeled "110 volts AC". What isthe expression for the voltage provided by a wall
socket? What is its rms value?
Modems
The word "modem" is short for "modulator-demodulator."
Modems are used not only for connecting computers totelephone lines, but also for connecting digital
(discrete-valued) sources to generic channels. In thisproblem, we explore a simple kind of modem, in which
binary information is represented by the presence orabsence of a sinusoid (presence representing a "1" and
absence a "0"). Consequently, the modem's transmittedsignal that represents a single bit has the form
Within each bit interval
, the amplitude is either
or zero.
What is the smallest transmission interval that
makes sense with the frequency
?
Assuming that ten cycles of the sinusoid comprise a
single bit's transmission interval, what is thedatarate of this transmission scheme?
Now suppose instead of using "on-off" signaling, we
allow one of several
different values for the amplitude during any transmission
interval. If
amplitude values are used, what is the resulting
datarate?
The classic communications block diagram applies to
the modem. Discuss how the transmitter mustinterface with the message source since the source
is producing letters of the alphabet, not bits.
Advanced modems
To transmit symbols, such as letters of the alphabet, RUcomputer modems use two frequencies (1600 and 1800 Hz)
and several amplitude levels. A transmission is sentfor a period of time
(known as the transmission or baud interval) and equals
the sum of two amplitude-weighted carriers.
We send successive symbols by choosing an appropriate
frequency and amplitude combination, and sending themone after another.
What is the smallest transmission interval that
makes sense to use with the frequencies given above?In other words, what should
be so that an
integer number of cycles of the carrier occurs?
Sketch (using Matlab) the signal that modem produces
over several transmission intervals. Make sure youaxes are labeled.
Using your signal transmission interval, how many
amplitude levels are needed to transmit ASCIIcharacters at a datarate of 3,200 bits/s? Assume use
of the extended (8-bit) ASCII code.
We use a discrete set of values for
and
.
If we have
values for amplitude
,
and
values for
,
we have
possible symbols that can be sent during each
second interval. To
convert this number into bits (the fundamental unit ofinformation engineers use to qualify things), compute
.
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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