Physics: Post your doubts here!

[Suchal Riaz]

Please read it:
In lecture i was taught things such as potential, electrical potential energy, drift velocity and much more. I didn't get anything.
At home i read coursebook, did test yourself question, end of chapter questions. Then i checked syllabus. Every point of syllabus had been covered in my private study that lasted a few days and i understood everything. I was happy that i had completed syllabus of electrocity but..
Now that i have open pacific physics and my lecture notes there are things which are not in coursebook or syllabus. Should i study them? Things such as drift velocity, electric potential energy, working of van der graaf etc despite the fact that they are not in syllabus?

 

[shikha95]

Can some explain question 5c(ii)?! It's M/J 2013 41. While finding EMF they do 2(magnetic flux linkage)/(time) even though the formula is EMF=(magnetic flux linkage)/time). Why?
The link to question paper: http://olevel.sourceforge.net/papers/9702/9702_s13_qp_41.pdf

 

[shikha95]

Please read it:
In lecture i was taught things such as potential, electrical potential energy, drift velocity and much more. I didn't get anything.
At home i read coursebook, did test yourself question, end of chapter questions. Then i checked syllabus. Every point of syllabus had been covered in my private study that lasted a few days and i understood everything. I was happy that i had completed syllabus of electrocity but..
Now that i have open pacific physics and my lecture notes there are things which are not in coursebook or syllabus. Should i study them? Things such as drift velocity, electric potential energy, working of van der graaf etc despite the fact that they are not in syllabus?

If it's not there in the syllabus, then there's no need to study it...unless you're done with everything and you're free, look through it.

 

[Suchal Riaz]

If it's not there in the syllabus, then there's no need to study it...unless you're done with everything and you're free, look through it.

Thnx for replying

 

[Saad Mughal]

Please read it:
In lecture i was taught things such as potential, electrical potential energy, drift velocity and much more. I didn't get anything.
At home i read coursebook, did test yourself question, end of chapter questions. Then i checked syllabus. Every point of syllabus had been covered in my private study that lasted a few days and i understood everything. I was happy that i had completed syllabus of electrocity but..
Now that i have open pacific physics and my lecture notes there are things which are not in coursebook or syllabus. Should i study them? Things such as drift velocity, electric potential energy, working of van der graaf etc despite the fact that they are not in syllabus?

Pacific is an old book and is not according to our CIE A'level Physics syllabus so those you can leave those topics if they are not in the syllabus.

 

[Saad Mughal]

can someone provide the notes that may help me understand the chapter "units" in a better way?

http://www.alevelhelp.com/physical-quantities-and-units/

 

[Lama AN]

Can someone explain for me the last part (b) ?? i ddnt get it .
its NOV\OCT 2008 V02 Q:2 part b

 

[Ahmad Shujah]

can someone solve them plz ?

 

[periyasamy]

Hai !This is a question from may june 2013 paper.Anyone can help me please?

 

[snowbrood]

Hai !This is a question from may june 2013 paper.Anyone can help me please?View attachment 32923

some important points
the nucleus is initally at rest so its momentum is zero
mass of neutron is equal to proton(
mass of electrons is negligible
lets consider the mass of neutron or proton equal to n
A is neuclon number which is number of protons+neutrons
total number of protons+neutrons times the mass of one of them
total sum of momentum before decaying=after decaying

(nA)*0=n(A-1)u-(n*1)v .

signs change as they are moving in opposite direction
rearraging it gives n(A-1)u=nV
dividing each side with n gives
(A-1)u=V

 

[snowbrood]

Hai !This is a question from may june 2013 paper.Anyone can help me please?View attachment 32923

nice question btw i liked it thanks pal

 

[periyasamy]

nice question btw i liked it thanks pal

Thaks a lot buddy.Any questions u have send it to me man.I can try to help u,man.

 

[periyasamy]

Hai ,can anyone help me to solve this doubt?Thanks a lot.Three question from may june 13.

 

[Jessie N.]

Hai ,can anyone help me to solve this doubt?Thanks a lot.Three question from may june 13.

Attached the solution for first question

2nd question pls visit this website： http://www.ocgi.okstate.edu/owpi/EducOutreach/Library/Lesson1_windenergycalc.pdf

3rd question also troubled me. seeking for help too.((

 

[periyasamy]

Attached the solution for first question

2nd question pls visit this website： http://www.ocgi.okstate.edu/owpi/EducOutreach/Library/Lesson1_windenergycalc.pdf

3rd question also troubled me. seeking for help too.((

Thank u Jessie

 

[snowbrood]

Hai ,can anyone help me to solve this doubt?Thanks a lot.Three question from may june 13.

Attached the solution for first question

2nd question pls visit this website： http://www.ocgi.okstate.edu/owpi/EducOutreach/Library/Lesson1_windenergycalc.pdf

3rd question also troubled me. seeking for help too.((

so lets solve 3rd question
simplify the branched resistors
simply the branch (2) the branch at left bottom 1/(1/1+1/1)=0.5ohm
lets simplify the branch (4) right bottom resistors in series are added so 1+1+1=3 ohm
this 3 ohm is parallel to 1 ohm so 1/(1/3+1/1) this simplified (4) to 0.75
all the resistors parralel to 3 volt will get 3 volt right?
so in top row voltage to the point the voltmeter is connnected is (1/2)*3=1.5v
in bottom row voltage to the point the voltmeter is connected is (1.5/2.25)*3=2v
since voltmeter measures the potiential difference it will be 2-1.5=0.5

 

[periyasamy]

so lets solve 3rd question
simplify the branched resistors
simply the branch (2) the branch at left bottom 1/(1/1+1/1)=0.5ohm
lets simplify the branch (4) right bottom resistors in series are added so 1+1+1=3 ohm
this 3 ohm is parallel to 1 ohm so 1/(1/3+1/1) this simplified (4) to 0.75
all the resistors parralel to 3 volt will get 3 volt right?
so in top row voltage to the point the voltmeter is connnected is (1/2)*3=1.5v
in bottom row voltage to the point the voltmeter is connected is (1.5/2.25)*3=2v
since voltmeter measures the potiential difference it will be 2-1.5=0.5
View attachment 32970[/quotE

so lets solve 3rd question
simplify the branched resistors
simply the branch (2) the branch at left bottom 1/(1/1+1/1)=0.5ohm
lets simplify the branch (4) right bottom resistors in series are added so 1+1+1=3 ohm
this 3 ohm is parallel to 1 ohm so 1/(1/3+1/1) this simplified (4) to 0.75
all the resistors parralel to 3 volt will get 3 volt right?
so in top row voltage to the point the voltmeter is connnected is (1/2)*3=1.5v
in bottom row voltage to the point the voltmeter is connected is (1.5/2.25)*3=2v
since voltmeter measures the potiential difference it will be 2-1.5=0.5
View attachment 32970

Thank u a lot.U rock buddy.

 

[Jessie N.]

so lets solve 3rd question
simplify the branched resistors
simply the branch (2) the branch at left bottom 1/(1/1+1/1)=0.5ohm
lets simplify the branch (4) right bottom resistors in series are added so 1+1+1=3 ohm
this 3 ohm is parallel to 1 ohm so 1/(1/3+1/1) this simplified (4) to 0.75
all the resistors parralel to 3 volt will get 3 volt right?
so in top row voltage to the point the voltmeter is connnected is (1/2)*3=1.5v
in bottom row voltage to the point the voltmeter is connected is (1.5/2.25)*3=2v
since voltmeter measures the potiential difference it will be 2-1.5=0.5
View attachment 32970

Awww thank you！！！so the 'All resistances are 1kΩ.' is just distracting. ˊ_>ˋ

 

[snowbrood]

Awww thank you！！！so the 'All resistances are 1kΩ.' is just distracting. ˊ_>ˋ

np just keep praying

 

[princess787]

Hey! Can anyone help me in p1 oct nov 2007! Question 23!! Very complicated!! It's about waves! Thanks ok advance! Really appreciate it!

 

[snowbrood]

Hey! Can anyone help me in p1 oct nov 2007! Question 23!! Very complicated!! It's about waves! Thanks ok advance! Really appreciate it!

23- B
Max speed = 2pi *a *f
f = ?
s = f* lamda
8 = f (50)
0.16 Hz = f

Max speed = 2pi * 2 * 0.16
=2 m/s
Max K.E. = .5 m* v^2 = 0.5 * 2 * 10^-3 * 2^2
= 4 mJ