Physics: Post your doubts here!

[Suchal Riaz]

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

its correct.
the new wave will have phase difference of 60 degree. which means that 1/6 of the one wavelength. which means one big block of 10 small blocks.
and the new amplitude will be √(2) of A.
which is almost 0.7a

 

[Snow Angel]

bi)
V= 230 -225 = 5
R=V/I =0.11ohm

bii)rho = 1.8*10^-8,Length = 16, Resistance = 0.11
R=rho*L/A
0.11=(1.8*10^-8*32)/A
A=5.3*10^-6 m^2

yes , but how is this ans the area of one of the wires. should nt we halve this answer?

 

[usama321]

View attachment 39471

It should be a straight line till at least 1.5A. V and I are directly proportional at lower temperatures. Straight at start, and curved at end, that's what the ms usually says

 

[Thought blocker]

yes , but how is this ans the area of one of the wires. should nt we halve this answer?

Suchal Riaz My teacher had not teach me anytime to half. Do we have to half ? :'(

 

[biscuitbiscuit]

okay so the range is from 1.5 to 3.5 V for 0-25 C
Volt meter reads only upto one decimal place, 0.1 V. 0.1V/1V * 25 C = 2.5 C. it means that the temperature can be known close to 2.5 C of the real values.
and secondly the circuit has another problem. the line is not straight. so same change for temperature is not same change for voltage for all values. it changes.

I didn't get this thing, did u mean 1.5 to 3.5 ohms if not how did you get volts?

 

[itallion stallion]

Plz help me with May June 2013 paper 41 question 5 part cii and question 11 part biii.
Thanks a lot!

 

[Snow Angel]

Suchal Riaz My teacher had not teach me anytime to half. Do we have to half ? :'(

Suchal riaz is ur teacher??

 

[Thought blocker]

Suchal riaz is ur teacher??

no, I tagged him coz MY teacher in India have not teach me such thing

 

[usama321]

Suchal riaz is ur teacher??

The wires are in series with each other. Just think of them as lying end to end. Won't you take the length of the whole wire, and calculate the cross sectional area of the wire? That's why you don't halve it

 

[Thought blocker]

The wires are in series with each other. Just think of them as lying end to end. Won't you take the length of the whole wire, and calculate the cross sectional area of the wire? That's why you don't halve it

Other wise we would halve it, eh ?

 

[usama321]

Other wise we would halve it, eh ?

why would we halve it? what is your approach of thinking when you say we would halve it?

 

[Thought blocker]

why would we halve it? what is your approach of thinking when you say we would halve it?

Snow angel asked why we dont half it. So I never halfed the area! So I am doing right or wrong ? ?

 

[usama321]

Had they been parallel to each other, we would have taken the length of only one wire, and then added their resistances by the parallel addition method

 

[Thought blocker]

Had they been parallel to each other, we would have taken the length of only one wire, and then added their resistances by the parallel addition method

Ok

 

[Snow Angel]

The wires are in series with each other. Just think of them as lying end to end. Won't you take the length of the whole wire, and calculate the cross sectional area of the wire? That's why you don't halve it

ok thnx

 

[meerul264]

Can someone please explain me the concept behind this question?

Q6
http://papers.xtremepapers.com/CIE/...nd AS Level/Physics (9702)/9702_s10_qp_22.pdf

And when it asks for line of best fit, do you draw a curve or a straight line of best fit? (Silly question, I know)

Thanks

 

[Hassan Ali Abid]

Can anyone plzz explain me the following part :-

Q. Use Lenz's law to explain why the input p.d and output e.m.f are not in phase. [2]

 

[usama321]

Can someone please explain me the concept behind this question?

Q6
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_22.pdf

And when it asks for line of best fit, do you draw a curve or a straight line of best fit? (Silly question, I know)

Thanks

Here

CB also has resistance. So there is some voltage across it too. The rest of the voltage is then equally dissipated across the two parallel wires

 

[Thought blocker]

Can someone please explain me the concept behind this question?

Q6
http://papers.xtremepapers.com/CIE/Cambridge International A and AS Level/Physics (9702)/9702_s10_qp_22.pdf

And when it asks for line of best fit, do you draw a curve or a straight line of best fit? (Silly question, I know)

Thanks

Line of best fit means a st. line

 

[Fahm Deen]

Oct/Nov 2010 /21 6.b . Please give me the solution with complete explanation. URGENT