Physics: Post your doubts here!

[Thought blocker]

Yeah

Then please solve it for me

 

[biscuitbiscuit]

Then please solve it for me

a) Power is directly proportional to V^2, Resistance is constant.
Therefore % reduction is, (230)^2-(220)^2/(230)^2*100 = 8.5%

b)(i) ammeter reading would be zero since p.d. is zero when C is at A
(ii) at B the p.d. would be 1.5 and according to the formula, I=V/R, I= 1.5/0.5= 0.3A

c(i) You have to plot these points on the graph and draw a line of best fit.
(ii) Read the current when l= 50cm
(iii) V= IR, therefore V= 0.12*5= 0.6V

 

[Thought blocker]

a) Power is directly proportional to V^2, Resistance is constant.
Therefore % reduction is, (230)^2-(220)^2/(230)^2*100 = 8.5%

b)(i) ammeter reading would be zero since p.d. is zero when C is at A
(ii) at B the p.d. would be 1.5 and according to the formula, I=V/R, I= 1.5/0.5= 0.3A

c(i) You have to plot these points on the graph and draw a line of best fit.
(ii) Read the current when l= 50cm
(iii) V= IR, therefore V= 0.12*5= 0.6V

I dont get a part.

 

[biscuitbiscuit]

I dont get a part.

which one?

 

[Thought blocker]

which one?

6a

 

[biscuitbiscuit]

6a

There is a formula for power, P=V^2/R. Since in the question they said that wire has constant resistance therefore power is proportional to voltage ^2

 

[Thought blocker]

There is a formula for power, P=V^2/R. Since in the question they said that wire has constant resistance therefore power is proportional to voltage ^2

I still not getting it, anyways thank for help.

 

[biscuitbiscuit]

I still not getting it, anyways thank for help.

Sorry I couldn't help you. Is it the formula? Don't ask me to derive it because I really don't know! They are couple of formulae of power used in this chapter like Power= V^2/R, Power= VI and Power= I^2R. You do take maths, right? because this is something like ratio thing

 

[Thought blocker]

Sorry I couldn't help you. Is it the formula? Don't ask me to derive it because I really don't know! They are couple of formulae of power used in this chapter like Power= V^2/R, Power= VI and Power= I^2R. You do take maths, right? because this is something like ratio thing

Tell me What formula you used ? I mean Tell me what values you input in V^2/R ?

 

[Suchal Riaz]

yup

Do you want me to explain?

 

[biscuitbiscuit]

Tell me What formula you used ? I mean Tell me what values you input in V^2/R ?

Hope this helps

 

[NinjaInPyjamas]

Do you want me to explain?

yes please ^_^

 

[Thought blocker]

View attachment 39453 Hope this helps

ty

 

[biscuitbiscuit]

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

 

[Snow Angel]

hi can u please explain the following questions? can u also plz draw the sketches and post it?
question 7b) from: papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w04_qp_2.pdf

question 5a) and 6b) from: papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w07_qp_2.pdf

 

[Suchal Riaz]

yes please ^_^

okay so it is very simple:
difference in pressure = rho g (difference on height)
difference in height= 6
only D and C had difference of 6
the height of column attached to high pressure will have smaller height.
so D is answer.

 

[Suchal Riaz]

hi can u please explain the following questions? can u also plz draw the sketches and post it?
question 7b) from: papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w04_qp_2.pdf

question 5a) and 6b) from: papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w07_qp_2.pdf

 

[Suchal Riaz]

hi can u please explain the following questions? can u also plz draw the sketches and post it?
question 7b) from: papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w04_qp_2.pdf

question 5a) and 6b) from: papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_w07_qp_2.pdf

 

[Suchal Riaz]

please so 5(a) of that paper i have got to go

ty

 

[Thought blocker]

please so 5(a) of that paper i have got to go

Sure :
5a)
its easier if u convert the angle in radian ie multiply by (π/180°) ----> 60° = π/3 rads.
n c this --->
thts whr the new wave will start!

So it would look like :

Correct me if it is wrong. ZaqZainab Suchal Riaz