Physics: Post your doubts here!

[Mohammed salik]

Any One?

Some One Plz DRAW THEM Plz..!
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_23.pdf Q6 C )iv)


http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w13_qp_21.pdf Q5)b)

Thnx In ADVANCE..!

 

[AhsanAfzal]

for definition emf should we write work done in driving a unit charge around a circuit or should we write chemical energy converted to electrical energy per unit charge?

 

[Suchal Riaz]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s11_qp_21.pdf
Q1 b part complete

resistivity = R A/L = 7.5* pi r² / 1.75 m = 7.5* pi (0.38 e -3 /2)² / 1.75 m = 4.86e-7

in this curly d(somthing)/something = percentage uncertainty
so dp/p = 3/1750 + 2*0.01/0.38+0.2/7.5 * 100= 8.13%
dp = 8.13% * 4.86e-7 = 0.395e-7

in this e is shortcut for writing X10^

 

[Suchal Riaz]

for definition emf should we write work done in driving a unit charge around a circuit or should we write chemical energy converted to electrical energy per unit charge?

it depends on the marks though. i have only seen energy converted into electric form of energy when in columb of charge passes through complete loop in markschemes

 

[TheJDOG]

for definition emf should we write work done in driving a unit charge around a circuit or should we write chemical energy converted to electrical energy per unit charge?

Second one

 

[Suchal Riaz]

Any One?

after 1/4 T the wave will be a straight line. to see why the antinodes go back to their original position(complete one oscilation in one T) so in 1/4th they complete 1/4th of their oscillation. which is from max to zero, then from zero to min, then from min to zero then from zero to max.

 

[Mohammed salik]

after 1/4 T the wave will be a straight line. to see why the antinodes go back to their original position(complete one oscilation in one T) so in 1/4th they complete 1/4th of their oscillation. which is from max to zero, then from zero to min, then from min to zero then from zero to max.

How would we draw that onto The Exam paper?

 

[Suchal Riaz]

How would we draw that onto The Exam paper?

draw a straight line
like this:

 

[Mohammed salik]

draw a straight line
like this:

In Both of them?

 

[Mohammed salik]

Because Some People Suggested This https://www.xtremepapers.com/community/attachments/untitled-png.42529/ ?????
Is This Right?

 

[Suchal Riaz]

 

[Mohammed salik]

View attachment 42553

Whats The diffrence Between two Question?
Why did u Draw like this For http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w13_qp_21.pdf
But Diferrent for Other One?

 

[MiniSacBall]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s10_qp_22.pdf

Q4 c)

Why λ/4, why not λ/6 or λ/8...etc.
Explain please?

 

[Suchal Riaz]

Whats The diffrence Between two Question?
Why did u Draw like this For http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w13_qp_21.pdf
But Diferrent for Other One?

the first one is stationary and second one is progressive

 

[Mohammed salik]

the first one is stationary and second one is progressive

Ohhhhhhh Okk.. This is what i was Missing.. The first one in http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w13_qp_21.pdf Is Transverse,,! Thanx Mann.. NOw i compleely Get it!

 

[Suchal Riaz]

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

Q4 c)

Why λ/4, why not λ/6 or λ/8...etc.
Explain please?

at lowest frequency the first harmonic is made which is 1/4 λ in case of closed pipe
so L=1/4 λ so λ=4L
you can't make a wave smaller than this because there must be a node at closed end and antinode at open end

 

[Suchal Riaz]

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

Q4 c)

Why λ/4, why not λ/6 or λ/8...etc.
Explain please?

for smallest case there is only one node and antinode so:

distance b/w antinode and node is 1/4 λ

 

[Usman Chughtai]

http://papers.xtremepapers.com/CIE/...vel/Physics (9702)/9702_s12_qp_23.pdfMay/June 2012 paper 23
question 1 c(ii) part 1

Veactor triangle one

help please

 

[randomcod]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s08_qp_2.pdf
Q6 all Powers please!! Dunno how to do it

 

[mehria]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s08_qp_2.pdf
Q6 all Powers please!! Dunno how to do it

(a) P=V^2/R
R=V^2/P = (240)2/(1.5 x 10^3)
=38.4 ohms

(b)
when the powers r in series then we will add their reciprocals n when they r in parallel then we will add their values...
1. there will be no current so no power will generate
2. when S2 is closed then current will choose the low resistance path n will only flow through one heater.. so 1.5kW
3. all of them r closed.. no current is passing through B.. so we will simply add the powers that r in parallel with eachother.. 3 kW
4. the current is passing through A and B... so we will add the reciprocals of the powers n the ans will be 0.75 kW
5. Current is passing through all the heaters so... 0.75 + 1.5 = 2.25 kW