A2 Physics | Post your doubts here

[angelgirl:)]

can anybody define FM plz?

 

[histephenson007]

can anybody define FM plz?

It is when the carrier wave frequency is modulated according to the displacement of the signal wave. Am I right?

 

[angelgirl:)]

http://www.xtremepapers.com/CIE/International A And AS Level/9702 - Physics/9702_w07_qp_4.pdf
How do you do 7c)
please help!!

in 9s very little decay of barium..since its half life is 1080s...
for Kr in zero second its no. is x...wen it becomes half in 3s it becomes x/2..in 6s its x/4..in 9s its x/8...
so from ratio ba/kr...x/(x/8)=8...
hope u get it

 

[angelgirl:)]

It is when the carrier wave frequency is modulated according to the displacement of the signal wave. Am I right?

i got it as ...f of carrier waves varies in (synchrony ) with signal in (synchrony) with displacement of signal...
but i want a simple and correct defination

 

[angelgirl:)]

wats bandwidth?

 

[nerdybookworm]

First things first: Dear Moderators,
I have been facing difficulty when it comes to finding A2 posts at the threads you have so kindly created for a more organized look. However, I wanted to see a separate thread for A2 questions and A2 questions alone. So, I came up with this thread.
Truth be told, A2 is very different from AS and the queries related to them are entirely different since there are different topics involved. I hope you understand.

My first A2 question: Can anybody please explain to me what 'infinite input impedance' means?

The pd across the input terminal is high and the current is low..

 

[angelgirl:)]

The pd across the input terminal is high and the current is low..

means infinite input resistance...

 

[nerdybookworm]

means infinite input resistance...

yes

 

[angelgirl:)]

ppl plz define bandwidth...

 

[SkyPilotage]

June 2009 P4 Q2 a) :- Why is the rate of alpha particles seem constant?
Answer in markscheme:- half life is very long/ but when I calculate half life by ln2 / decay constant its very shoort 1.98 x19^-7...
Am I missing something? I think I am, the constant rate is Delta N / Delta t not the decay constant right?

 

[SkyPilotage]

ppl plz define bandwidth...

range of frequencies , where the maximum frequency is subracted from the lowest frequency!

 

[angelgirl:)]

range of frequencies , where the maximum frequency is subracted from the lowest frequency!

cant we define it llike this...the capacity of electricle signal at which information is transfered...?

 

[aliya_zad]

in 9s very little decay of barium..since its half life is 1080s...
for Kr in zero second its no. is x...wen it becomes half in 3s it becomes x/2..in 6s its x/4..in 9s its x/8...
so from ratio ba/kr...x/(x/8)=8...
hope u get it

Thank you!!
Was Struggling a lot with this question..

 

[SkyPilotage]

cant we define it llike this...the capacity of electricle signal at which information is transfered...?

i would not use this, maybe you can top it. but dont use it alone just to be on the same side.

 

[angelgirl:)]

Thank you!!
Was Struggling a lot with this question..

u welcome...

 

[angelgirl:)]

range of frequencies , where the maximum frequency is subracted from the lowest frequency!

y have to be subtracted from the lowesr f only?

 

[miss irfan]

please tell how to draw the diodes in june 2010 paper 41 Q6

 

[SkyPilotage]

y have to be subtracted from the lowesr f only?

remember the sidebands? Bandwidth is highest freq ( fc+fm) - lowest freq (fc - fm ) = 2fm = bandwidht

 

[ABDSyed]

Assalam Wa Alikum​

Plz Someone could show me how Q6 C(ii) to be done and its calculation​

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s03_qp_4.pdf​

(ii) Determine the activity A of the sample 5.0 years after purchase, expressing the
answer as a fraction of the initial activity A0. That is, calculate the ratio .
ratio = ………………………………….. [2]
A
–––
A0

 

[miss irfan]

apart from bridges where else is strain gauge used?