Physics: Post your doubts here!

[Mobeen]

hi,
May/june 10/43 q6 b1
anyone plz...

 

[omg]

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w09_qp_51.pdf
q1. wht is the method 2 check the fundamental frequency?????
and for the experiment. we'll add water in the bottle 2 reduce the vol of air in it????

 

[waleedsmz]

hi,
May/june 10/43 q6 b1
anyone plz...

Please copy the exam link next time...

If your question is the one about magnetic fields, then:

i) Since you have moving electrons ( moving charges ) therefore you have a current. As you have a magnetic field perpendicular to the direction of this current, therefore there will be a force on the current ( the electrons ) and they will deflect. Keeping in mind that the force is perpendicular to both the direction of the magnetic field and the direction of the current.

ii) Using fleming's left hand rule. Having the current finger ( middle finger ) to the right since the direction of the electrons is opposite to the direction of the current ( because they're negatively charged ) and the index finger pointing downwards. Thumb will point to QR so it will move there.

Hope that helped. : )

 

[Hussnain]

One complete cycle has phase angle 360 deg. 60 deg means one-sixth cycle.
T2 is one-sixth cycle behind T1, or 1/6 period behind.
According to the graph, the period is 3 sec.
T2 is then 0.5 sec behind T1.
Graph:
View attachment 7512

still couldn't get the point

 

[Hussnain]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_w04_qp_2.pdf
AS PHYSICS
Q1(b)(ii). Q3(c),(e)(ii). Q4(c)
Q5(b)(i)(ii)(iii). Q6(b), (c)
Please answer as soon as possible.

 

[Nikesh]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w02_qp_2.pdf
AS PHYSICS
Q5 (b)(i)
Phase angle.
Please answer as soon as possible.

U have formula for phase angle, P(let phase angle) = t/ T(time period) * 360 as a complete cycle denotes 360 degree
use this to calculate value of t....
phase angle = 60 as T2 lags behind by 60 degree
T= 3 secs (Time period of given wave)
now,
60 = t/3 * 360
i.e. t = 0.5 secs
as amplitudes and waveform is same, draw a curve which is 0.5 sec behind the given curve as shown by Dragoncub.

 

[omg]

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_w11_ms_51.pdf
pls pls pls pls cn i get a diagram fr q.1???

 

[NIM]

i need som small and good notes abut physics....
so blind in Phy...

 

[Rabib_69]

CAN ANYONE EXPLAIN TO ME WHY ORBITS ARE OF IMPORTANCE? (2 marks)

 

[omg]

how to draw a hall probe for the exp design qs???????????????????
PLEASEEEEEEEEEEEEEEEEEEEEEE helpppp any11111111

 

[raamish]

http://www.xtremepapers.com/papers/...nd AS Level/Physics (9702)/9702_s11_qp_22.pdf

Qs 1c(i) For this qs i applied the formula s=ut+0.5at2. I put 20 as (u) in the formula to get the answer. But in the marking scheme the u has been taken as 0. Please help.

Qs 5a(iii) I did: P=I2R
2.5*2.5*3.3=20.625. But in the marking scheme the solution and answer are different.

 

[histephenson007]

i need som small and good notes abut physics....
so blind in Phy...

http://www.xtremepapers.com/revision/a-level/physics/

 

[pratikdahal]

no idea about this question ..
please help me with this !!
thank you in advance

 

[hassam]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s03_qp_4.pdf
5 d ii ...cn u tell where ,ark shud be.....shud it ne on the bottom line of square

 

[Zishi]

View attachment 7563 no idea about this question ..
please help me with this !!
thank you in advance

At t=0, the mass of iron will be zero grams. After 2.6 hours, mass of iron will be 0.7 micrograms. At t=5.2 h, mass of iron will be (0.7+0.35) micrograms. When m grams of manganese decays, it produces n grams of iron because both of them have same Ar. Do you get it now?

 

[Zishi]

http://www.xtremepapers.com/papers/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s03_qp_4.pdf
5 d ii ...cn u tell where ,ark shud be.....shud it ne on the bottom line of square

Yes, it should be on bottom line of the square. Mark scheme just says that in different words. . .

 

[pratikdahal]

At t=0, the mass of iron will be zero grams. After 2.6 hours, mass of iron will be 0.7 micrograms. At t=5.2 h, mass of iron will be (0.7+0.35) micrograms. When m grams of manganese decays, it produces n grams of iron because both of them have same Ar. Do you get it now?

It was very helpful....!!
furthermore, how can we calculate the time at which the ratio of (mass of iron-56) / (mass of manganese-56 ) is equal to 9.0 ?

 

[Zishi]

It was very helpful....!!
furthermore, how can we calculate the time at which the ratio of (mass of iron-56) / (mass of manganese-56 ) is equal to 9.0 ?

At that time % of manganese is reduced to its 1/10th value to form 9/10 of iron(as 9/10 of manganese is decayed). Then use x = xo(exp)-λt by putting x=1/10 times xo.

 

[pratikdahal]

I

At that time 9/10 of manganese is reduced to its 1/10th value to form 9/10 of iron. Then use x = xo(exp)-λt by putting x=1/10 times xo.

I am sorry, 'cause i don't get how come "9/10 of manganese is reduced to its 1/10th value to form 9/10 of iron"??
can u just elaborate a bit more

 

[Zishi]

I
I am sorry, 'cause i don't get how come "9/10 of manganese is reduced to its 1/10th value to form 9/10 of iron"??
can u just elaborate a bit more

Oh, sorry - my wording went wrong. I've edited the original post.