How was physics paper 4

[leosco1995]

Yeah it was the amplitude in some SHM question in 42.

 

[ganapathynar]

Does someone remember the last part in question 2. about internal energy and whether the change in temperature will be less or more than 297?

 

[Jinkglex]

temp was below 297.

And we didnt get any question about SHM of any needle and we gave paper 42 :s wtf?

 

[ganapathynar]

temp was below 297.

And we didnt get any question about SHM of any needle and we gave paper 42 :s wtf?

Not every physics paper has SHM about Needles, i only saw that in 2 papers

 

[megamind]

megamind said: ↑

thanks gary 221,but you are wrong,DAC and the serial to parallel are not the smae
check this diagram out(mobilephone flow chart)
if they are the same why are they kept seperate
​

ADC = samples the signal at regular intervals. for each sample, produces an 8- bit binary no. So DAC = will convert the binary no to a decimal no ie to an analogue signal.
Parallel to serial = takes the 8 bits from 1 sample n places them after the 8 bits from the previous sample to produce a continuous series of binary digits.
So, serial to parallel must do the opp. ie assemble the 8 bits, n pass them to the DAC for conversion into analogue. then, pass the next 8 bits to produce the next signal, n so on.
Did I say tht they both r the same??
I guess not : "The serial to parallel converter n the DAC produce an analogue signal" does not imply they r same.
And if I did say they r same, sorry, m bad!!


ANYONE WHO READ THIS 2 FREE MARKS

 

[ganapathynar]

megamind said: ↑

thanks gary 221,but you are wrong,DAC and the serial to parallel are not the smae​

check this diagram out(mobilephone flow chart)​

if they are the same why are they kept seperate​

​

ADC = samples the signal at regular intervals. for each sample, produces an 8- bit binary no. So DAC = will convert the binary no to a decimal no ie to an analogue signal.
Parallel to serial = takes the 8 bits from 1 sample n places them after the 8 bits from the previous sample to produce a continuous series of binary digits.
So, serial to parallel must do the opp. ie assemble the 8 bits, n pass them to the DAC for conversion into analogue. then, pass the next 8 bits to produce the next signal, n so on.
Did I say tht they both r the same??
I guess not : "The serial to parallel converter n the DAC produce an analogue signal" does not imply they r same.
And if I did say they r same, sorry, m bad!!


ANYONE WHO READ THIS 2 FREE MARKS

Obviously they are not the same! For one thing they have different names!

 

[Your-Blood]

Not every physics paper has SHM about Needles, i only saw that in 2 papers

It was a mass on spring

 

[Afifa m Afzal]

This is one of the most easiest papers ever. Anyone who got like a C in their AS can jump to an A. InshAllah.

 

[ganapathynar]

This is one of the most easiest papers ever. Anyone who got like a C in their AS can jump to an A. InshAllah.

Is it possible to jump from a B to an A*?

 

[FRENZYAMU]

Awkward in sense that the pattern was really much changed. No op amp circuits plus I was highly expecting MRI to come.
And for SHM apmlitude was 0.021m

no but the q said write expression in cm of how s related to t

 

[FRENZYAMU]

temp was below 297.

And we didnt get any question about SHM of any needle and we gave paper 42 :s wtf?

how ws temp below 297 ? r u sure

 

[pansyflower]

i wrote same but i gave a diff reason i referred to newton's laws :/

your answer is right

 

[fathimaash]

no but the q said write expression in cm of how s related to t

The qus just askd u to relate the equations dats all...

 

[Jinkglex]

how ws temp below 297 ? r u sure

first we give 95 joules
then we take out 125 joules
overall system has net loss of 125-95= 30J
since no thermal energy given/taken from system
system falls even further below 297
as 297 would have been if 0 joules loss/gain.

 

[FRENZYAMU]

The qus just askd u to relate the equations dats all...

yes but whether amp to be used as 0.021 or 2.1

 

[fathimaash]

yes but whether amp to be used as 0.021 or 2.1

U were suppose to write 0.021 not 2.1..

 

[Your-Blood]

NO!
There was nothing such written & we had to write in m not cm.

For displacement
X = 0.021 Cos (w) t [Can't remember what was omega)

For Velocity
V = - 0.021 Sin (w ) t x (w)

 

[FRENZYAMU]

U were suppose to write 0.021 not 2.1..

i did do it in metres for the calculation for energy, but i have a strong feeling it ws written in cm in the q for equation cuz before putting the values i ws seriously considering whether they wanted it in m or cm,,,,oh well maybe i did write 0.021

 

[ganapathynar]

NO!
There was nothing such written & we had to write in m not cm.

For displacement
X = 0.021 Cos (w) t [Can't remember what was omega)

For Velocity
V = - 0.021 Sin (w ) t x (w)

Unfortunetly the question said what was the numerical expression for X cm. So everything had to me in cm not m. The velocity was however m/s

 

[HunzaZ]

how ws temp below 297 ? r u sure

Wasn't the temp below 297? It was, gas was expanding, it cools on expanding.