Physics: Post your doubts here!

[1357911]

Thank you
Thank you very much

My pleasure.

Anytime.

 

[Musab100]

My pleasure.

Anytime.

can u answer AS chemistry question ??

 

[Musab100]

My pleasure.

Anytime.

can u answer AS chemistry question ??

 

[BAOOZHEN]

HEY everyone please very important for the practical, the last 2 questions always state 4 sources of errors and improvements, please can someone help me with this

 

[hassankhan]

can u answer AS chemistry question ??

which question?

 

[sellinimmie]

Hello! I'm going to take Paper 3 (AS Practical Skills) this Thursday, and I have a few questions about the exam..
-Are we allowed to bring calculators?
-When are we supposed to repeat readings? Is it when they ask for 6 sets of readings then we're expected to have two readings for one set? For example, when asked for the voltage between a length of a wire, we're going to give two voltage readings for that length, then get their average?

ok so calculators are allowed. about the readings, i figured 6 are enough and what needs repeating are the first instructions/questions before that.

 

[sellinimmie]

HEY everyone please very important for the practical, the last 2 questions always state 4 sources of errors and improvements, please can someone help me with this

Answers are in the Mark Schemes here: http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/

Here are some common answers..
Limitations:
- two results not enough
- measurement of radius/distance/etc. not accurate
- difficult to stop stopwatch at correct moment
Improvements:
- take more readings and plot a graph
- use vernier caliper/travelling microscope
- record using video camera, play in slow motion & use a timer

 

[sellinimmie]

Someone please answer: Is there a proper angle (from the vertical axis) for the starting position of a pendulum when finding its oscillation's time period? Should the bob be raised at a small angle so it would move slow?

 

[danyaljamil]

Someone please answer: Is there a proper angle (from the vertical axis) for the starting position of a pendulum when finding its oscillation's time period? Should the bob be raised at a small angle so it would move slow?

no unless mentioned just displace the bob enough so that you can easily track its oscillations and measure its time period

 

[sellinimmie]

no unless mentioned just displace the bob enough so that you can easily track its oscillations and measure its time period

ok. thanks

 

[Namit Verma]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s08_qp_4.pdf Can anyone explain q6.a ? And for 5.b what do they expect us to draw? should we just draw 2 capacitors in series connected in parallel to another 2 capacitors in series ( total 4 capacitors ).. Cause that makes the whole capacitance = 4500 µF

 

[1357911]

http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s08_qp_4.pdf Can anyone explain q6.a ? And for 5.b what do they expect us to draw? should we just draw 2 capacitors in series connected in parallel to another 2 capacitors in series ( total 4 capacitors ).. Cause that makes the whole capacitance = 4500 µF

Q-5b. yes its 2 in series with one in parallel.

 

[IR Germany]

help please, question 7 http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s07_qp_1.pdf

 

[Namit Verma]

help please, question 7 http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s07_qp_1.pdf

According to the diagram, v = u + X. For the motion of a particle in a straight line with uniform acceleration, v=u+at. So X=at . Answer C

 

[Namit Verma]

Q-5b. yes its 2 in series with one in parallel.

Okk and the others?

 

[1357911]

Okk and the others?

Im sorry. We havent yet started those chapters.

 

[IR Germany]

question 14 please http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s08_qp_1.pdf

 

[IR Germany]

question 14 please http://papers.xtremepapers.com/CIE/...and AS Level/Physics (9702)/9702_s08_qp_1.pdf

 

[IR Germany]

According to the diagram, v = u + X. For the motion of a particle in a straight line with uniform acceleration, v=u+at. So X=at . Answer C

thank you but what does it means with the force is not the same direction as the initial velocity?

 

[JessieN.]

http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_w12_qp_21.pdf

4（b)(iii) plsss help!!!

nλ = 2 × 625 is a constant (1250) C1 n = 1 → λ = 1250 outside visible
n = 3 → λ = 417 in visible
n = 4 → λ = 312.5 outside visible
λ=420nm

Really don't understand what the answer says, can someone please explain for me?? Thanks!!!

 

[danyaljamil]

http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_w12_qp_21.pdf

4（b)(iii) plsss help!!!

nλ = 2 × 625 is a constant (1250) C1 n = 1 → λ = 1250 outside visible
n = 3 → λ = 417 in visible
n = 4 → λ = 312.5 outside visible
λ=420nm

Really don't understand what the answer says, can someone please explain for me?? Thanks!!!

strange question okay here goes remember that maxima and minima are formed at alternating points for e.g if n=1 is maxima then n=3,5,7 can only be used for the n values the angle and grating are the same so dsinO is a constant and nλ should be equal to it so just put in the n values in that and find the corresponding wavelenght for this question n=3 gives 417nm so 420nm to 2 s.f hope this helped