Recent content by americast

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    I Huygen's principle in practical sense

    Thanx! Your answer was precise and helpful...Any ideas about the second point...? Gramercy...
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    I Huygen's principle in practical sense

    Hello everyone, I have two little clarifications to make about Huygen's principle: - Why doesn't the wave go backward? I mean, if every point on the plane acts as the source of a secondary wavelet, then, along with the envelop which makes the wave travel apparently forward, another should...
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    I Time lag before application of force

    I meant to say that I am willing to find after how much time the effect of the field created by both the charges at time t=0 will be felt by the charges, i.e. after how long will the charges feel force acting on them due to the field created by them at time t=0. Assuming that the charges were...
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    I Time lag before application of force

    Hi everyone, I present a situation here: Say there are two points A and B in space separated by a distance d. I create two charged particles (of any charge) at points A and B at time t=0. After how long will they experience force due to one another? My answer: We know that electric fields...
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    Boiling point and vapour pressure

    Exactly. The very small fraction of water vapour present above the boiling water should have been in equilibrium with the liquid. Now I understand that this does not happen as convection takes those vapours away from the surface of the boiling liquid. Thanx a lot!
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    Boiling point and vapour pressure

    But, why not? While boiling, the entire air (including the small fraction of vapour) above the liquid is at the vapour pressure of that liquid (at that particular temperature). So, at least, the vapours of the liquid should be in equilibrium with the liquid. That is how vapour pressure is...
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    Boiling point and vapour pressure

    Thanx... I think I have got it! Say, while boiling, the air above the liquid comprises 1% vapour (of that particular liquid) and rest ordinary air (other gases). In this situation, the liquid is in equilibrium with that 1% of its vapours only while it is not in equilibrium with the rest of the...
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    Boiling point and vapour pressure

    Okay. So, at the boiling temperature, the liquid is in equilibrium with its vapours, not the entire air, right? Can you tell me why does a liquid boil only when the outside pressure is equal to its vapour pressure at that temperature? What is the reason behind this phenomenon?
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    Boiling point and vapour pressure

    Hi all, I am facing difficulty in understanding the reason behind the fact that a liquid boils when the atmospheric pressure is equal to its vapour pressure. We know that at the vapour pressure, the air and the liquid remain in equilibrium, so there's no net evaporation or condensation. So...
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    What's the Flaw in De Broglie's Derivation of Wave-Particle Duality?

    Hi all, De Broglie had proposed the theory of wave particle duality. But I don't understand how the relation λ=h/(mu) holds true. I will tell you why: De Broglie's derivation: E=mc2 and E=hv So mc2=hv Thus, λ=h/(mc) and for particles its h/(mu). I have a problem in the last line...
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    What is the significance of d (x^2-y^2) in the d subshell?

    Hi all, One of the orbitals of the d subshell is called d (x^2-y^2). What is the reason behind that? It would be helpful if someone could give the calculations. Thanx in advance...
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    Black body radiation and particle nature of light.

    Okay. So, Planck himself did not know that he was assuming the particle nature of light, right? thanx...
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    Coordinate geometry with area of triangle

    The radius is 2sqrt(2). The height required for the triangle to be of area 1 unit is 1/sqrt(2). The max height Is 2sqrt(2) (radius).1/sqrt(2) being smaller can be on either side. Since the base it the diameter, it is a right triangle. For both sides it would be 2*2=4. Thanx...
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    Black body radiation and particle nature of light.

    Thanx a lot for your replies... So, here I am drawing a short inference: The particle nature of light was not known when Reyleigh-Jeans derived a formula on the basis of the Poynting formula. It worked for low frequencies but in higher frequencies (such as for UV), they fail and this is...
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