A2 Physics P4 Questions ONLY

[Champ101]

Thank you! Though I didn´t understand "so, gain= 0/Vin (Vin = V2-V1)" and the jump to using potential divider formula.

Oh let me try again

Vout= O.

Gain= Vout/ (V2-V1)

Gain = O/(V2-V1)

Gain* (V2-V1) = O

either Gain = O or (V2-V1) = O

So thats how we get V2=V1

 

[periyasamy]

Oh let me try again

Vout= O.

Gain= Vout/ (V2-V1)

Gain = O/(V2-V1)

Gain* (V2-V1) = O

either Gain = O or (V2-V1) = O

So thats how we get V2=V1

Bro see my explanation.

 

[Namehere]

Oh let me try again

Vout= O.

Gain= Vout/ (V2-V1)

Gain = O/(V2-V1)

Gain* (V2-V1) = O

either Gain = O or (V2-V1) = O

So thats how we get V2=V1

Perfect!

 

[Champ101]

Thank you! Though I didn´t understand "so, gain= 0/Vin (Vin = V2-V1)" and the jump to using potential divider formula.

Potential divider stuff...

So when we consider the line with strain gauge.

Take the the point (that small round circle) and find the potential at the point.

The formula is: Vout = Vin*R2/(R1 + R2)

So what we do is find Vout here. (which in this sum is V1)

here Vin= 4.2 v, R2 is the resistance of strain guage.

 

[Namehere]

Potential divider stuff...

So when we consider the line with strain gauge.

Take the the point (that small round circle) and find the potential at the point.

The formula is: Vout = Vin*R2/(R1 + R2)

So what we do is find Vout here. (which in this sum is V1)

Yeah got it! ^^ Its incredible, I´ve learned more here in 15mins than two years with my teacher!

Btw, for part (iii) you get Vout as -0.12V, what does the negative sign indicate?

Thank you!

 

[A*(a*)]

Would you mind (everyone) writing down the question paper and question number, just so anyone can look at it.

June 04

 

[unique111]

**In an Op-amp, when Vout= 0 does that mean both input voltages from inverting and non-inverting are equal?
Help please!***

And question no. 10c ii) http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_41.pdf

Ques 10b) ho to draw the switch with the relay?
http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_s10_qp_42.pdf

 

[Champ101]

Sorry for that...
The last part,,,iam sorry.Here's the way....First u get v2--->(1000/1128)*(4.5-0)-----u use the pd concept here.
Then to get v output use the formula given---->12*(4-3.99)
Sorry for the mIstakes. HAHA!!

Hey bro i checked your work! V comes to 4.5 Volts actually? can you check?

 

[A*(a*)]

Since ideal gas's internal energy is directly proportional to the temperature, del u will be 0. Wince it is being compressed, the volume decreases and W=+. To make the U=O, Q=-
Heating of a solid without expansion. Heating=+, without expansion means del W is 0 thus overall u=+
As for ice, im a little unsure about it, but still, ill give it a shot. Q=+ as energy is required to weaken the bongs to convert it into water. Since ice is less dense than water, when it will melt, it the density will increase which means volume will decrease, thus W=+ and U is positive.
Just remember, when volume increases, W=-, when volume decreases, W=+.
When energy is supplied, Q=+, when Q=-, energy is given out. And U=del W + del Q.

Man you were so helpful,
May God bless you the only mistake you did was w=+ in the end, it is w=0 in ms. any idea, how?

 

[Champ101]

Yeah got it! ^^ Its incredible, I´ve learned more here in 15mins than two years with my teacher!

Btw, for part (iii) you get Vout as -0.12V, what does the negative sign indicate?

Thank you!

Oh yeah! Its actually op-amp acts as a comparator.
some theory here: For comparator,
if V+ > V-, then Vout = +ve and vice versa.

In our case, v-= v1 =4 V and v+=v2=3.99, so the output will be negative as v+ < v-

 

[Champ101]

**In an Op-amp, when Vout= 0 does that mean both input voltages from inverting and non-inverting are equal?
Help please!***

And question no. 10c ii) http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_41.pdf

Ques 10b) ho to draw the switch with the relay?
http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_s10_qp_42.pdf

Yeah when Vout = 0, Vin = Vout

 

[periyasamy]

Hey bro i checked your work! V comes to 4.5 Volts actually? can you check?

4.5 is the given one,rite.

 

[Champ101]

4.5 is the given one,rite.

oh yeah! got confused lol btw thats a really smart working bro!

 

[boxfire1995]

Man you were so helpful,
May God bless you the only mistake you did was w=+ in the end, it is w=0 in ms. any idea, how?

Nope, i have no idea why w will be 0. Im sorry. Ill ask my teacher and get back to you, okay?

 

[Namehere]

Nope, i have no idea why w will be 0. Im sorry. Ill ask my teacher and get back to you, okay?

Maybe work is done by the gas, rather than work done on it (the system).

 

[periyasamy]

oh yeah! got confused lol btw thats a really smart working bro!

Haha,thanks bro!!

 

[stareaj]

may 2005 q 7 c pls ASAP

 

[stareaj]

ITS ON NUCLEAR CHP FIND TIME WHEN RATIO IS 9
please

 

[Namehere]

so4_4: Q5(d ii) Why is it 3.0A? and not 1.12A?

 

[Namehere]

so4_4: Q5(d ii) Why is it 3.0A? and not 1.12A?

and on the same question paper, Q5(a), I don´t get the anwer in the ms.