Physics: Post your doubts here!

[xyn1123]

time for 9.5 cycles is 6 x time base setting i.e. 6x(0.01) = 0.06
time period = 0.06/9.5
frequency will be 1/Ans
its close to 140
so answer is B

Is it 8.5 cycle?

 

[x-gamer-x]

Is it 8.5 cycle?

yup it is

i corrected

any ways my logic was correct

 

[xyn1123]

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_s08_qp_1.pdf
Q14, 18,24,37

 

[Jacob Park]

can I get some help again. thank you so much

 

[Jinosupreme]

Guys need help here.Please help.Thanks a lot.
Question 29--answer is c
Question 31--answer is c

29. As u put a screen to view ur interference pattern, u will definitely put at XY
31. U need to draw the positive and negative charge of the electric field. Which is positive on top, negative at bottom due to the direction of the electric field. Hence positive part of the Rod move to negative side. Negative part of rod move to positive side. The forces are in opposite direction, which causes 0 resultant force. But there is a torque, which will move in direction of anticlockwise of u imagine how the positive turns towards negative and the negative turns towards positive.

Hope this helps

 

[periyasamy]

29. As u put a screen to view ur interference pattern, u will definitely put at XY
31. U need to draw the positive and negative charge of the electric field. Which is positive on top, negative at bottom due to the direction of the electric field. Hence positive part of the Rod move to negative side. Negative part of rod move to positive side. The forces are in opposite direction, which causes 0 resultant force. But there is a torque, which will move in direction of anticlockwise of u imagine how the positive turns towards negative and the negative turns towards positive.

Hope this helps

Thank u.Have any question?

 

[Jessie N.]

Ok no problemo.For the question no33,i think it a bit logically.Path B shows path taken by proton.So now for helium nucleus it is
4 1
2 he 1 p.
------------>the helium is much heavier than the proton.....So,it would need a greater distance to be completely deflected than
the proton..For the direction,it should be same as the proton as both r same charge.

For the second question mean power dissipated is done by calculating the= highest power+lowest power/2
Highest power=i^2*r==>2^2*100=400 watt
lowest power=-1^2*100=100watt
400+100/2=250 watt

For the third question,,
option a rite-----Because when the s1 is closed,althugh s2 is also closed,the current will instead pass the region
without resistance,path s1.So the overall circuit becomes like the original circuit above.The r at s2 have no effect onn the current reading

option b rite--i think u know why.Its exactly similar to above circuit.No current flow to the bottom R thus,same ammeter reading

option d rite-----no current flow as switch all open.No complete cicruit

Option c is WRONG.When s1 is open n S2 is closed,the current must now pass the extra resistor as it has no other chance.Thus overall resistance
is higher n current value is less than I.

Awwww thank you o(≧▽≦)o

 

[periyasamy]

Awwww thank you o(≧▽≦)o

No problem.U helped me a lot.A bit that i could repay.

 

[periyasamy]

Hai guys anyone help me with this question .Get the upperpart of graph but cannot analyse the lower part of graph.Thanks
Ans is a.

 

[periyasamy]

29. As u put a screen to view ur interference pattern, u will definitely put at XY
31. U need to draw the positive and negative charge of the electric field. Which is positive on top, negative at bottom due to the direction of the electric field. Hence positive part of the Rod move to negative side. Negative part of rod move to positive side. The forces are in opposite direction, which causes 0 resultant force. But there is a torque, which will move in direction of anticlockwise of u imagine how the positive turns towards negative and the negative turns towards positive.

Hope this helps

Boss,,I am so sorry but want to ask u why do u say the movement anticlockwise.I dont really get it.

 

[periyasamy]

Boss,,I am so sorry but want to ask u why do u say the movement anticlockwise.I dont really get it.

I got it man.Thanks.

 

[Jessie N.]

Could you guys help me plz?

Is the answer B ?

 

[Jessie N.]

Could you guys help me plz?

View attachment 33174

Hope my answers are correct >~<

 

[Jessie N.]

http://papers.xtremepapers.com/CIE/Cambridge%20International%20A%20and%20AS%20Level/Physics%20(9702)/9702_s08_qp_1.pdf
Q14, 18,24,37

o(^▽^)o

 

[periyasamy]

Hai guys need help here.What does this question asks?
in which order of magnitude are the frequencies of electromagnetic waves in the visible
spectrum?
A-10^12hz
b-10^13hz
c10^14hz
d10^15hz
Why ais the answer c?
Thanks....

 

[Jessie N.]

Hai guys need help here.What does this question asks?
in which order of magnitude are the frequencies of electromagnetic waves in the visible
spectrum?
A-10^12hz
b-10^13hz
c10^14hz
d10^15hz
Why ais the answer c?
Thanks....

Wavelength of visible spectrum is between 400~750nm
So the frequency is in between 4*10^14 ~7.5*10^14 Hz
Thus ans is C

 

[Jinosupreme]

Erm help please，thanks ˊ・ω・ˋ

18. Conservation of energy
1/2mv^2 = mgh + 1/2mv^2
Cancel all the m
(28)^2/2 = (9.81)(22) + v^2/2
Then u should be able to calculate the v

21. The key word is CONSTANT RATE OF FLOWING OF WATER
Hence there will be no increase in velocity along X to Y
But because water is forced to flow constantly, hence gain in Elastic Potential Energy. Lost in GPE because decrease in h.

33 Not sure

 

[Jessie N.]

Help please！！ans is B and D

 

[Jessie N.]

18. Conservation of energy
1/2mv^2 = mgh + 1/2mv^2
Cancel all the m
(28)^2/2 = (9.81)(22) + v^2/2
Then u should be able to calculate the v

21. The key word is CONSTANT RATE OF FLOWING OF WATER
Hence there will be no increase in velocity along X to Y
But because water is forced to flow constantly, hence gain in Elastic Potential Energy. Lost in GPE because decrease in h.

33 Not sure

thanks anyway！

 

[Jessie N.]

I think I get Q33
Just find the ratio of cross sectional area I guess, it will be 1:16, so resistance is 0.2*16= 3.2