Chemistry / biology /physics applications

[XPFMember]

Assalamoalaikum wr wb!

I need help in Q:10 (c) of Nov:2007.
Can you please explain how do I draw the graph?

And also if possible, can you give me an answer for Q:9(c) of the same paper?
Is this correct?

A transducer is placed in contact with the skin, with a gel acting as a coupling medium, so as to reduce the size of impedance change thereby reducing the reflection. Short pulses of ultrasound are transmitted into the body, part of which gets reflected at boundaries between the tissues. These reflected pulses are detected by the transducer and are then transformed into voltage pulses. These voltage pulses can then be amplified and processed.

I don't know how to mention the last 2 points? Just as mentioned in the ms...or do i specify A and B scans?

Here's the ms http://www.xtremepapers.com/CIE/International A And AS Level/9702 - Physics/9702_w07_ms_4.pdf

 

[XPFMember]

Assalamoalaikum wr wb!

One point for physics application:

For MRI...in the booklet it says hydrogen atoms resonate and all that stuff, but note that the ms/er said that students werent clear and incorrectly referred to as hydrogen atoms instead of nuclei....so make sure u use the word nuclei and not atoms....

and I need help with the amplitude modulation graph...booklet says that it is sum of three frequency..something like that ...but i dont really get that! plz..hassam if u cud...or if anyone else doing that..
and the attached file may be a bit useful for amplitude modulation..

 

[hassam]

for the graph in question 10 c.....since it is amplitude modulation.....frequency of modulated wave will be same as carrier wave....i.e 50 KHz....this corresponds to a time period of 20microseconds.....while the change in amplitude from max-min-max will occur with a frequency of 5KHz ...i.e frequency of information signal....this corresponds to a time period of 200 microseconds.wave will be like that shown in attached pic....just change the values in time-scale

for question 9(c)no need to mention why gel is used.....other is correct but must also include the following line:the time between the transmission of pulse and its receipt back at the transducer gives info as to the distance of boundary from the transducer.the intensity of reflected pulse gives info as to nature of the boundary.

 

[XPFMember]

Assalamoalaikum wr wb!
Jazakallah Khairen
Just one more thing..do we have to start from maximum always or that doesn't matters?

 

[hassam]

Assalamoalaikum wr wb!
Jazakallah Khairen
Just one more thing..do we have to start from maximum always or that doesn't matters?

yea thats upto you!

 

[hassam]

PRODUCTION OF MONOCLONAL ANTIBODIEShttp://highered.mcgraw-hill.com/sites/0072556781/student_view0/chapter32/animation_quiz_3.html

 

[hassam]

sorghum's BULLIFORM CELLShttp://en.wikipedia.org/wiki/Bulliform_cell

 

[shimeka]

Thank you so much for all the interesting videos you all posted! Its really going to be of much help!!!!

 

[hassam]

http://www.sciencedaily.com/releases/2011/03/110301122053.htm

 

[farhan143]

Do you have animations based on chapters of as content on Physics, Biology as well as Chemistry learning from animation is much more easier to understand...
I AGREE!

 

[girlscampisra]

can anyone please post videos related to communication information?

 

[histephenson007]

Cystic fibrosis is an autosomal recessive disease in which
thick mucus is produced in the lungs and airways. The gene
responsible for this disease codes for a protein composed of
1,480 amino acids. In most patients with cystic fibrosis, the
protein has 1,479 amino acids: A phenylalanine is missing at
position 508. A baby is born with cystic fibrosis. He has an
older brother. How would you test the DNA of the brother to
determine if he is a carrier for cystic fibrosis? How would you
design a gene therapy protocol to “cure” the cells in the lung
and airway?

Is this an actual past paper question? Is it from Biology or chemistry?

 

[hassam]

can anyone please post videos related to communication information?

 

[histephenson007]

Sadly, youtube is blocked in China.... TT.TT

 

[fawaid]

Assalamu alaikum warahmathullah
Is it possible to post notes from the Pearson book(i assume direct sensing notes are from it) for medical physics and communications part as well?
Jazakallahu Khairan

 

[raza786]

are the sites given after every topic in bio applications worth looking into?

 

[raza786]

are the sites given after every topic in bio applications worth looking into?

 

[XPFMember]

are the sites given after every topic in bio applications worth looking into?

assalamoalaikum wr wb!

i dont think so

Well...for bio i guess, u just need to know what all is in the booklet...that's it...?!

 

[zain942010]

Please i want any teacher's notes on telecommunications or any link other than application booklet Exams r near help me please !

 

[fawaid]

Assalamu alaikum warahmathullah
Is it possible to post notes from the Pearson book(i assume direct sensing notes are from it) for medical physics and communications part as well?
Jazakallahu Khairan

Someone please upload these sections.It will be a great help.

Barakallah