Physics: Post your doubts here!

[Jinosupreme]

Answer is C, anyone explain?

I really don't get this one, help anyone, answer is D

 

[Jinosupreme]

Can anyone explain

Answer is 2 and 3. Why?

And

Answer is D. Is it because it is impossible to be 0A current when there is max PD?

 

[smoothieoeek]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_11.pdf
Q37 please
Dont understand why you need E2 to work out the P.D

 

[periyasamy]

Hai guys,anyone can explain why is z compression?I think i know why point x n y is tension as it is against weight.

 

[periyasamy]

speed 33 m s^–1
density of the air is 1.2 kg m^–3.
The wall has an area of 12 m^2
What is the force?
First u relate with ur data givien,
So to relate
Density = mass/volume
How u get volume from data?
The only way is to to relate speed and area.
Speed multiply with area
33 X 12 = 396m^3 s^-1

Relate density with this data
1.2 kg m^-3 X 396m^3 s^-1 = 475.2 kg s^-1
Now how to relate to force?
F=ma
F=m(v-u)/t

Since u found m/t = 475.2
Sub ur values
Force = 475.2 (33 - 0)
Force = 15681
= 16000N

Good job buddy.Nice explanation.Exeptional........

 

[periyasamy]

Answer is C. Always see this question, but never really understands it.

Anyone explain? Answer B

Boss ,1st question option a and d cannot as the emf never changes in whatever situation.It is the p.d that differs.How can it be work overcome against resistor??.It must be internal resistance because it is not the overall voltage that is significant here but it is the p.d across dry cell(overcome internal resistance..

For the 2nd question current increases as current will have an option to flow between the two junctions shown.Instead of flowing through resistor,it would follow the bottom path tthat is without any resistor.So lesser resistance,higher current.
The voltage decreases to zero because no current will flow to the upper part of junction.
Sorry man,if i confuse u .I hope it helps.

 

[Isaac CKR]

Why is the answer D?

 

[periyasamy]

Answer is C, anyone explain?

I really don't get this one, help anyone, answer is D

For the 1st question,its simple.Get the volume by density formula.Then square root it with 3 n u will gwt the distance.
I am not sure with the second one.

 

[periyasamy]

Can anyone explain

Answer is 2 and 3. Why?

And

Answer is D. Is it because it is impossible to be 0A current when there is max PD?

Bro for 1st question I am not sure.My logic is this,the gradient is FL/AX
Gradient of p much steeper than q.So the young modulus of p must be greater than q
However,based on m=fl/ax,u find out than when gradient value is larger,extension is smaller.Than shows option a is wrong.
I guess u understand 2 and 3 as option 2 is calculation n 3is theory which is rite.

For the next question,its a concept whereby when no current,there is no current flowing there is no p.d.
when pd is low that is when the resistor show min value,the overall resistance decreases...So current exceeds to high value.

 

[Jinosupreme]

For the 1st question,its simple.Get the volume by density formula.Then square root it with 3 n u will gwt the distance.
I am not sure with the second one.

Just found out how to do 2nd one,
Use formula s=ut + 1/2at^2
Firstly
x = 0 + 1/2a(t1)^2
Next
x + h = 1/2a(t2) ^2

Sub together
1/2a(t1)^2 + h = 1/2a(t2)^2
And I think u know how to move the rest into correct places Thanks a lot!

 

[periyasamy]

Hello guys.Does the term increase in separation of fringes means that the x value in formula lamda=ax/d increase or decrease?Thank u.

 

[periyasamy]

Just found out how to do 2nd one,
Use formula s=ut + 1/2at^2
Firstly
x = 0 + 1/2a(t1)^2
Next
x + h = 1/2a(t2) ^2

Sub together
1/2a(t1)^2 + h = 1/2a(t2)^2
And I think u know how to move the rest into correct places Thanks a lot!

Thank u boss.

 

[Jinosupreme]

Hai guys,anyone can explain why is z compression?I think i know why point x n y is tension as it is against weight.

U imagine ur hand curve into the same shape, u will realised the part of Z is a compression. Just like when u bend a eraser, there will be a tension on top, but compression below

 

[periyasamy]

U imagine ur hand curve into the same shape, u will realised the part of Z is a compression. Just like when u bend a eraser, there will be a tension on top, but compression below

Thanks man,super example.

 

[periyasamy]

Hai guys,need help here.
My question is if question ask maximum kinetic energy than it is in positin2 ,rite?Thank u.....

 

[smoothieoeek]

plz help

 

[smoothieoeek]

and this plz~

 

[periyasamy]

plz help

plz help

cant open your document.

 

[1357911]

http://freeexampapers.com/index.php... Level/Physics/CIE/2008 Nov/9702_w08_qp_5.pdf
Q-2 part d and e???

 

[smoothieoeek]

cant open your document.

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w09_qp_12.pdf
ok Q11 & 12