A2 Physics | Post your doubts here

[Mobeen]

A sinusoidal carrier wave has frequency 500 kHz and amplitude 6.0 V. It is to be
frequency modulated by a sinusoidal wave of frequency 8 kHz and amplitude 1.5 V.
The frequency deviation of the carrier wave is 20 kHz V–1.
Describe, for the carrier wave, the variation (if any) of
A: amplitude
B: Frequency

can sum1 plz tell the answer of part B?? how to calculate the frequecy?
thanks!

frequency varies 20Khz V-1 . so total variation is 20 x 1.5 = 30KHz. max frequency is 530KHz and min frequency is 470kHz

 

[Mobeen]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w08_qp_4.pdf
Q1bi....plz help?

there is no centripetal force on the poles so the normal reaction would be less .

 

[waleedsmz]

Yes it is, its in almost every year!

I think you mean the kinetic energy one.... Not this one... I believe we don't have to derive this...

 

[hassam]

well guyx tell the last tipss.....share the new things u learnt while solving past papers....

 

[Mobeen]

there is a problem with my adobe, please can you see the question and answer?

i dont get it either :/

 

[miss irfan]

can anybody else answer then? please?

 

[hassam]

explain why it is necessary to make repeated amplifications of signal......
signal loose energy as it travels....so must be amplified in order to prevent the signal from being lost in the noise.....
In order that a signal may be detected adequately, its power must be a minimum number of times
greater than the power associated with noise.....this ratio is the signal to noise ratio

 

[hassam]

who is 100% ready for tomo..exam ?

ready!!!! ask any problem

 

[smzimran]

who is 100% ready for tomo..exam ?

I am

 

[histephenson007]

Well, guys, I'm going to sleep now. Need to be fresh for tomorrow's exam! Thank you all for participating in this forum and teaching me some valuable tips to get me as ready as I can be for tomorrow's exam. May one and all do well in the exam and achieve your desired results!

 

[smartangel]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s09_qp_4.pdf
Q11 b iii. last part of the question..please explain working!!

 

[NyTRiDr]

frequency change= 20khz*1.5=+-30 so the frequncy fo the carrier wave will change by \+- 30 (470-530)Khz frequency

thanks!

 

[Jonathan127]

Could someone please help me with the graph on Q10 c) ? How would you draw it?
http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w07_qp_4.pdf

 

[histephenson007]

@smzimran
Thank you for pointing it out. I'll make sure that I will use the previous answers in my calculations.

 

[smzimran]

@smzimran
Thank you for pointing it out. I'll make sure that I will use the previous answers in my calculations.

Best of Luck brother!
Btw, what is your location ?
If its Pakistan, isn't it too early to sleep? Not even Isha prayer time has come

 

[hm12]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s08_qp_4.pdf
http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s08_ms_4.pdf
please can anyone explain question 6 part (a) part (b) (i) and (b) (ii)

 

[Mobeen]

Could someone please help me with the graph on Q10 c) ? How would you draw it?
http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w07_qp_4.pdf

jut draw a AM signal graph with modulating frequency of 5kHz(200us) and carrier frequency of 50KHz(20us)

 

[smartangel]

ready!!!! ask any problem

i"ve posted a question above..plz help me out with it!

 

[sheekha]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s08_qp_4.pdf
anyone for 9 (b).
thanks in advance!

 

[angelicsuccubus]

do we have to know about helical springs?