Physics: Post your doubts here!

[biscuitbiscuit]

For the same current, there is higher V across C than in the resistor. At 5v or above, even though the current in the resistor will be more than in C, the Voltage across C would be 5v out of the total of 7, thus again making the power dissipated across it higher.

View attachment 39428

This is what i don't get, after 5V for the same current resistor R has greater voltage than component C

 

[usama321]

This is what i don't get, after 5V for the same current resistor R has greater voltage than component C

You have got to see the current now, not voltage. The voltage across the two components would be different as they are in series now. in series the current is the same. Therefore, you will have to see the voltages for the same amount of curent

 

[NinjaInPyjamas]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_11.pdf

q23

 

[usama321]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_11.pdf

q23

Total constant of the three forces would be:
For the two above, it would be 2k. Now, add the third one,
1/2k + 1/3k = 5/6k = 6/5k (Just add them together like you do in parallel circuits when they are connected end to end)

W = 6/5k * x
x = W *5/6k = A

 

[usama321]

Suchal Riaz I'd suggest you add this question to your difficult questions thread. I found it difficult.
https://www.xtremepapers.com/community/attachments/screenshot_2014-04-19-11-12-02-png.39406/

 

[NinjaInPyjamas]

Total constant of the three forces would be:
For the two above, it would be 2k. Now, add the third one,
1/2k + 1/3k = 5/6k = 6/5k (Just add them together like you do in parallel circuits when they are connected end to end)

W = 6/5k * x
x = W *5/6k = A

thanks a lot!

 

[NinjaInPyjamas]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_11.pdf

20 and 21 please

 

[biscuitbiscuit]

You have got to see the current now, not voltage. The voltage across the two components would be different as they are in series now. in series the current is the same. Therefore, you will have to see the voltages for the same amount of curent

In previous post you said that voltage across 'C' would be 5v out of 7, how did you get that?

 

[NinjaInPyjamas]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_11.pdf

why is 15 not A?

 

[usama321]

In previous post you said that voltage across 'C' would be 5v out of 7, how did you get that?

Nah, i was saying that just to eliminate any factor of doubt. Just to clarify, the current in the circuit can not increase more than around 2.5, because after that, the combined p.d across the two components would become more than the emf... Thus before the value of around 2.5 ma, all the values of the pd across C are more than the resistor, leading to more power being dissipated across it.

 

[usama321]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_11.pdf

why is 15 not A?

because weight always acts downwards. Thus it would be .15 *tan 30

 

[Thought blocker]

because weight always acts downwards. Thus it would be .15 *tan 30

tan 30 ?

 

[biscuitbiscuit]

Nah, i was saying that just to eliminate any factor of doubt. Just to clarify, the current in the circuit can not increase more than around 2.5, because after that, the combined p.d across the two components would become more than the emf... Thus before the value of around 2.5 ma, all the values of the pd across C are more than the resistor, leading to more power being dissipated across it.

Thank you sooo much!

 

[Suchal Riaz]

Suchal Riaz I'd suggest you add this question to your difficult questions thread. I found it difficult.
https://www.xtremepapers.com/community/attachments/screenshot_2014-04-19-11-12-02-png.39406/

Is the answer D

 

[usama321]

Is the answer D

yup

 

[Thought blocker]

Is the answer D

yes

 

[Thought blocker]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_13.pdf
Q11 and 26 Plz Thanks
Thought blocker

Q26 is solved.

for 26 answer is B
since 2 x distance between 2 nodes=wavelength
so as in 1m 3nodes are there ,the distance between 2 nodes =1/3=o.333
hence wavelength=2 x o.333=0.666m
so f=330/o.666=495Hz

Q11 :¬

P initial = 2mu - mu =mu
And for momentum to be conserved, P ini = P final
So check it for all question..
Option A)
-((2mu)/3)+(5mu/3) = 3mu/3 = mu so momentum is conserved Pi = Pf
Option b)
-((2mu)/6)+(2mu/3) = 1/3mu = Momentum is NOT conserved Pi =/(not equal) pf
So answer is option B

 

[biscuitbiscuit]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s10_qp_22.pdf
'Q6(d)', pleasee

 

[Thought blocker]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_22.pdf
'Q6(d)', pleasee

Can U solve whole question 6 except D ?

 

[biscuitbiscuit]

Can U solve whole question 6 except D ?

Yeah