Physics: Post your doubts here!

[hussamh10]

increase of wavelength decreases the brightness.
Reducing the slit separation, a therefore results in the increase in the width of fringes.
making each of the double slits narrower, increases the brightness and the width of fringes is unchanged.

The brightness of fringes increase by
1)Intensity /enrgy/powerrating of the source inciedenting light on double slits increasees
2)Decrease the distance bw the double slit
3)E=1/Lamda so decrease the wavelentgh and Intensity will increase .
4)Increase the WIDTH of both slits without changing the seperation (a) betwenne slits.

 

[hussamh10]

Can you please let me know how it'll be drawn?
will it go far or lag behind the original line?

It will go far as speed is increase as well as no air resistance

 

[emkay]

Can you please let me know how it'll be drawn?
will it go far or lag behind the original line?

Since the air resistance is negligible, with greater horizontal speed the new path will lead ahead but it must obey the parabolic motion.
i have attached an image, hope it helps.

 

[queen of the legend]

please explain : question 4c ( 22/2010)

 

[geek101]

queen of the legend
nov or june?

 

[queen of the legend]

queen of the legend
nov or june?

june, my last post has the qp and ms

 

[raamish]

Since the air resistance is negligible, with greater horizontal speed the new path will lead ahead but it must obey the parabolic motion.
i have attached an image, hope it helps.

how will the ii) part be done of this question. Will it lag behind?

 

[emkay]

how will the ii) part be done of this question. Will it lag behind?

definitely, yes. it will be just like (G) but lagging behind the shown path that is due to the presence of air resistance
in the opposite direction which reduces the speed.

 

[geek101]

june, my last post has the qp and ms

since its the lowest frequency, and the speed is constant so it will be the max wavelength, due to their inversely proportional relationship. max wavelength >> when there will be only one node, on the closed end, and one antinode on the open end. and the distance between them is 45 cm
which means 45 cm >> 1/4 lambda
so 1 lamba = 45 x 4 x 10^-2 = 1.8 m
frequency = speed / lambda
= 330 / 1.8
= 180 Hz

 

[raamish]

definitely, yes. it will be just like (G) but lagging behind the shown path that is due to the presence of air resistance
in the opposite direction which reduces the speed.

awsum thnx know the answer to Qs 5a(ii) and (iii) of W11 22?the potentiometer one

 

[emkay]

awsum thnx know the answer to Qs 5a(ii) and (iii) of W11 22?the potentiometer one

go here: http://www.xtremepapers.com/community/threads/physics-post-your-doubts-here.9860/page-154
Post# 3068 by queen of the legend.

 

[queen of the legend]

m stuck in calculating the resultant intensity in question 5 c ii
oct/2005

 

[aiskw1]

The brightness of fringes increase by
1)Intensity /enrgy/powerrating of the source inciedenting light on double slits increasees
2)Decrease the distance bw the double slit
3)E=1/Lamda so decrease the wavelentgh and Intensity will increase .
4)Increase the WIDTH of both slits without changing the seperation (a) betwenne slits.

Hello, I just wanted to ask a question...

I've never seen the equation E=1/Lamda before... is it A2?
it would be helpful if you could explain it, thank you

 

[zephyr86]

Hi.can someone explain m/j 08 q 6(b)?
Thanks.

 

[Lyfroker]

How to calibrate a spring balance?

sm1 plz tell me.....

 

[BettyBoop]

http://www.xtremepapers.com/papers/...and AS Level/Physics (9702)/9702_s06_qp_2.pdf
question 5.c) someone help?

 

[hussamh10]

Hello, I just wanted to ask a question...

I've never seen the equation E=1/Lamda before... is it A2?
it would be helpful if you could explain it, thank you

Yeah it is A2 but our Sir just explained the concept with this formula that if Wavelength decrease the intensity increases u dont have to remember its just for concept

 

[geek101]

Hello, I just wanted to ask a question...

I've never seen the equation E=1/Lamda before... is it A2?
it would be helpful if you could explain it, thank you

the speed of the wave will remain constant. therefore from the formula v = f . lambda you can say that :
lambda = v / f , and becuz v is constant, lambda is inversely proportional to frequency. We know that (frequency)^2 is directly prop. to intensity. Therefore if the wavelength increases >> frequency decreases >> intensity decreases.

 

[Silent Hunter]

and about memorising the wavelengths of spectrum ? do we need to learn the ranges too or any value in between the specific ranges?

 

[geek101]

Hi.can someone explain m/j 08 q 6(b)?
Thanks.

apply the formula P = V^2 / R for each. V is always 240V.
scenario 1 is pretty obvious.
here i drew the circuits for each of them, i ignored the branch for every open switch.

2) switch 2 is closed. now B is in parallel with a wire which has negligible resistance, and because in parallel circuits the combined resistance is lesser than the lowest resistance, therefore the resistance in B >> 0 ohms. So the only R is >> 38.4 ohms of A.

3) B is again 0 ohms. Now A and C are in parallel.

4) A and B will now be in series. B is no more in parallel with the wire.

5) All three resistors will show their resistance. C is in parallel with A+B