All the relevant waves are electromagnetic waves. Sound waves are converted. Carrier waves are generated either in the phone or the transmitter (depending on which way the information is flowing). The carrier wave is an EM wave which has the characteristic of being able to travel sufficient distances (usually in the microwave region). The sound wave which is converted to an EM wave is then embedded in the carrier wave. Once it reaches its destination the carrier wave is stripped off.
@quantum3280
3 жыл бұрын
I’m not taking physics but I will soon, in college. I’m so excited and these videos have helped me learn so much and I have taken intense notes on every single video in this series now. Took me a couple of months but I’m now done with the series, thank you sir.
@geoffreyengatkinson
8 жыл бұрын
free quality education 😅cant imagine
@kanzaahmedchandio4348
6 жыл бұрын
yea, but witness it
@DrPhysicsA
12 жыл бұрын
One way of doing it is Frequency Division Multiple Access (FDMA) : FDMA separates the spectrum into distinct voice channels by splitting it into uniform chunks of bandwidth. Each call sends its signal at a different frequency within the available band per geographical cell. But there are other ways with digital communications. Wikieducator has a good pdf piece on cell phone technology.
@gpsinghgajju
12 жыл бұрын
thanks very much, after watching your your videos I realize that physics is not difficult to understand if you are taught properly. I learned more physics from your videos in two days than may be in two years in school. Its very exciting.
@jenko701
11 жыл бұрын
All your videos are just great , you just nail it every time .
@kpbnoc
7 жыл бұрын
I am very impressed. This is really free quality education. Thanks.
@timmytim9054
5 жыл бұрын
1:18 “coil of WAAAAAH”
@anayparikh3198
4 жыл бұрын
WAAAAIAAAAA
@DrPhysicsA
11 жыл бұрын
If you embed a signal within a carrier wave then there is a degree of uncertainty about the precise wavelength of the carrier wave. That uncertainty is really the bandwidth. It is the amount of the spectrum that is taken up to cover all the frequencies needed to be included in the signal such that there will be no interference with the signal embedded in a neighbouring carrier away
@LarsBerntzon
10 жыл бұрын
Very nice video covering a lot of good information. I detail: the AM modulation you are drawing is not quite like that in normal AM, what you have drawn is side band modulation where no effect is transmitted when the modulation signal is 0 v. With normal AM, the carrier voltage is half its max when modulation signal is at 0 V.
@linkchibi
12 жыл бұрын
THANK YOU VERY VERY VERY VERY MUCH , I WILL NEVER FORGET THIS KINDNESS PLEASE KEEP THE VIDEOS COMING . HAVE A NICE DAY SIR
@sohaibabbasi3355
4 жыл бұрын
9:35 i think you mean frequency of the wave
@alexchen2519
6 жыл бұрын
Im still not sure why the frequency of the signal is added to the frequency of the carrier wave. I thought AM has no effect on the frequency?
@mauthoormotasim6332
3 жыл бұрын
exactly mate. I don't understand too.
@DrPhysicsA
11 жыл бұрын
In an AM wave the carrier waves sine wave is itself modulated to carry the signal. The bandwidth is the degree of spread on the carrier wave.
@Alfster18
11 жыл бұрын
Great video, thank you! What do you mean when you talk about the bandwidth of the AM wave because you say that the amplitude is 20kHz but I thought amplitude was measured as a distance?
@mahmoudm451
7 жыл бұрын
at 9:00 what do you mean by "the amplitude is 20KHz" ? how is the amplitude measured in Hz?
@hadiyousef1704
7 жыл бұрын
He means to say the frequency is 20 kHz, just a silly mistake. well done for catching onto that!
@3551Bashir
11 жыл бұрын
definely a thumps up.
@leonardowilhelmdicaprio999
3 жыл бұрын
Thumbs, you mean?
@manahilkhan2555
6 жыл бұрын
OMG. NOW I UNDERSTAND THIS WHOLE TOPIC. THANKYOU SO MUCH! LOTS OF LOVE
@DrPhysicsA
11 жыл бұрын
More accurate to say that it will reduce the quality of the embedded signal, that is the actual signal which contains the information about sound etc.
@zawaideh61
8 жыл бұрын
hey sir, can you please do video on the attenuation per unit length of the signal??
@learnwithuziharry7035
5 жыл бұрын
A level physics?
@yuanhuilee3082
7 жыл бұрын
When he said BALLOON at 1.36 i laughed
@tahanikkhah2957
9 жыл бұрын
Thank you so much for providing this channel for us, helped me a lot !
@ArthurZH
8 жыл бұрын
The question now is why is there a bandwidth for AM. If I am merely manipulating my carrier wave's amplitude with respect to the signal, it's frequency should remain unchanged, right? Or am I getting something wrong here?
@lazeran
7 жыл бұрын
In combining the signal with the carrier you produce two side-bands, one on each side of the carrier.
@alexchen2519
6 жыл бұрын
Yes but WHYYYY?
@shifamuhammad7366
5 жыл бұрын
I’m confused about this too! Can someone please please please explain this
@noctavel
8 жыл бұрын
If the power of a mobile is so low, how can be possible for an receiver to get the signal from a mobile phone? can you make a video about it ? Thanks !!
@aishashar8302
7 жыл бұрын
Awesome...have got everything required..really great
@spdandavate123
11 жыл бұрын
very nicly put....i second the comment above...god bless u
@bushraimtiaz3723
7 жыл бұрын
Really informative. Thank you so much
@etiennesilvio
9 жыл бұрын
1000 Thanks for this video.!
@roykharal5978
8 жыл бұрын
well explained lectures
@adityanalwaya5502
10 жыл бұрын
First of all thank you sir for this wonderful explanation of Telecommunication I have one doubt here that if you are telling that for sending message to far distance we have to modulate it at higher Frequency But On the other hand FM (Which operates at higher frequency) travels less distance as compared with AM (Which operates at lower frequency) Why is it so can you please clarify that???
@DrPhysicsA
10 жыл бұрын
Long wave radio waves will certainly travel further but are subject to greater interference. FM has a better quality.
@Ashique4241532
11 жыл бұрын
Thank you SO SO SO much!!!
@nriver38
10 жыл бұрын
Sir, during your explanation of bandwidth, why did you use kilohertz as the unit of amplitude?
@DrPhysicsA
10 жыл бұрын
I was adopting too much of a shorthand. Amplitude is not measured in kilohertz.
@Hammadmk971
8 жыл бұрын
+DrPhysicsA what exactly were you referring to? Frequency or amplitude? I'm a little confused .-.
@leonardowilhelmdicaprio999
3 жыл бұрын
@@Hammadmk971 Frequency is measured in kilohertz.
@saadawan8283
5 жыл бұрын
Nice work.
@krishan
11 жыл бұрын
Hi i just don't quite get the bit about bandwidth, how come if you reduce the bandwidth leading to higher frequencies lost, that will reduce the quality of transmitted signal?
@geoffreyengatkinson
8 жыл бұрын
10 million thanks for this video
@bmodon6881
10 жыл бұрын
Thank you very much i have physix=cs exam tomorrow and i think i doing it well!!!!!
@DrPhysicsA
10 жыл бұрын
All good wishes for the exam.
@moshecohen-mn9cj
7 жыл бұрын
you are the best +DrPhysicsA
@Jayce1712
12 жыл бұрын
Thank you very much sir, you are a-w-e-s-o-m-e :)
@Antropovich
11 жыл бұрын
Is it really how ADC works? I mean to represent a wave with a certain amplitude in analog, it takes several waves to represent the same wave in digital... Which is the reason "you loose information density by converting from analog to digital"... Or am I missing something? I am referring to 16:50
@ahmadkathrada6026
11 жыл бұрын
sir thank u so much could u plz make a video about revision on all application question englobing direct sensing ,medical and telecommunication!!!BTW u are my hero!!!!!!!!
@OMAIMHREEM
11 жыл бұрын
Thank you Sir for the wonderful you tube. please give me detail explanation how is Microwave auditory effect this is what I mean microwave hearing, is modulated using satellite.
@zainabm9650
11 жыл бұрын
please tell me from where the carrier waves are transmitted??from a radio station?and how does the information signal attatch on the radio carrier waves??and the informaton signal refers to the sound waves??
@jacobvandijk6525
9 жыл бұрын
Is the carrier-wave digitalized too (before transmission)? And how does a digital signal move the electrons in the antenna (to create the EM-radiation)?
@DrPhysicsA
9 жыл бұрын
No. The carrier wave is just a straightforward Electromagnetic wave in the microwave region or radio wave region. There is no signal in it to digitise until you add the signal itself either in analog or digital form.
@jacobvandijk6525
9 жыл бұрын
DrPhysicsA Okay, thanks!
@shockingvideos5225
9 жыл бұрын
DrPhysicsA how varying voltage is applied?
@jacobvandijk6525
9 жыл бұрын
Animation The difficulty is that a lot of the time there is talk about waves, where in fact it's just signal-processing. The only real waves are the incoming soundwave and the outgoing radiowave; inbetween there is no wave.
@ashazwar6794
8 жыл бұрын
what to do mean around 14:30 by 200khz=15khz?
@DrPhysicsA
8 жыл бұрын
At 13:30 i say that FM equates to (rather than equals)
@gpsinghgajju
12 жыл бұрын
Hello, why does signal from one mobile does not interfere with another mobile close by, thanks.
@fenghc1
6 жыл бұрын
The ADC part: x axis should be time other than frequency. Am I right?
@pindiboii7247
3 жыл бұрын
no its at a particular instant of time so time is constant
@fareedaappa2327
7 жыл бұрын
wonderful
@microwavecoffee
3 жыл бұрын
THANK YOU
@ervinkiller
10 жыл бұрын
thank you very much.
@khizeriftikhar9157
6 жыл бұрын
Thanks again 😃
@crossvizannuff
7 жыл бұрын
Sir, thankyou very much!
@amroto97
9 жыл бұрын
In the Cambridge A level endorsed book, it is log(P2/P1), which is opposite to what you have explained can anybody clarify this for me ?
@esaskhan95
9 жыл бұрын
amr ramadan yep that was a little confusing
@zhen3356
9 жыл бұрын
amr ramadan you're forgetting the fact that he took P2 as Pin and P1 as Pout
@mohamedmahmoud-ze9sx
10 жыл бұрын
that was so helpful, thank you :)
@adithyarathnayake9797
6 жыл бұрын
Thank you
@zatulmutalif3230
11 жыл бұрын
sir what is bandwidth?? i dont really understand part 09:20...thank u:)
@glaiver4ever
11 жыл бұрын
well you basically mean 20KHz Frequency and not Amplitude of the info signal, right?
@maazmunir9213
5 жыл бұрын
Yes
@Sairam-ky2os
4 жыл бұрын
its wrong the bandwidth of AM depends on frequency of signal not amplitude of signal which is volts music consists of many frequiences superposed
@madarajkc
10 жыл бұрын
thanks :)
@jimmybar11
3 жыл бұрын
He is one in a million, best among many, most trusted , I almost gave up on trading then I met him through a friend, Austin is the most trusted trading expert who helped the life of my family and I ,.
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