# Search results for query: *

1. ### Time of Impact of Gas Molecules on the Inner Wall of a Pressure Vessel

In derivation of relation for pressure of Gas ,(see pic below) the time for rate of change of momentum of molecules should be the time for which the wall of the vessel and the molecules kept interacting with each other, not the time between successive collisions. As circumscribed below, my...
2. ### I Stability of Nuclei

Thank you Dr_Nate for the kind reply. All I am understanding from your replies is there is some special mechanism by which a nucleus absorb energies. I humbly submit I lack that knowledge and request to kindly share something about it. Is this absorption similar to an electron inside an orbit...
3. ### I Stability of Nuclei

I am thankful that the replies have helped me clarify many of my misconceptions. I have one more doubt in mind in support of my statement made earlier regarding breaking of nucleus. In Rutherford nuclear reaction where nitrogen is hit by alpha particles and oxygen and a proton are produced...
4. ### I Stability of Nuclei

Thanks Sir. It is very convincing argument. I am pleased and thankful for your time. High regards.
5. ### I Stability of Nuclei

Thanks for the reply. I correct myself. Sure sunlight falls short of binding energy of nucleus. But my question still stands. The thermal energy we provide during chemical reactions aren't sufficient enough to provide this required energy? Please reply with a little bit detail. Regards
6. ### I Stability of Nuclei

Hi I need help from PF scholars to figure out one difficulty in understanding stability of nucleus. Nuclei remain unaffected during chemical reactions taking place even at very high temperatures and pressures. But their binding energy figures are not that high. Such chemical reactions have heat...
7. ### Voltage across R, L and C vs AC Voltage source in RLC Series Circuit

Thanks. I need more help on this please.
8. ### Voltage across R, L and C vs AC Voltage source in RLC Series Circuit

One property of series resonance circuit is that at resonance, the voltage across circuit elements R,L and C may be larger than the source voltage. I can relate it to vector analogy where component vectors may have larger values than the resultant and the phenomenon is counter-intuitive. This...
9. ### Why does a capacitor charge to 63% of the applied voltage?

Thanks indeed. This is the best part of the discussion. I am way satisfied. Thanks to everybody who helped. You all are great people.
10. ### Why does a capacitor charge to 63% of the applied voltage?

Thanks indeed for the detailed explanation. I am sure I have lacked in exactly communicating my question and I added a clipping to support me to clarify. I understand in all you wrote above. I understand a capacitor keeps charging for infinite time and in every time constant there is an...
11. ### Why does a capacitor charge to 63% of the applied voltage?

It is very kind of you Sir to come for help. I am sure you will encourage to ask rather silly questions. I am sure these will bridge some knowledge gaps. Regards.
12. ### Why does a capacitor charge to 63% of the applied voltage?

Thanks Sir. You said that it was more of a definition. To my understanding definitions are man-made meant to simplify the things and once decided may be helpful to understand laws and principles.(I may be wrong). I have studied in this thread that it is not a Physics law or Principle (time...
13. ### Why does a capacitor charge to 63% of the applied voltage?

That is a brilliant analogy Sir, very helpful to understand capacitor working. I use another while teaching to my classes. Two identical water tanks connected thru a valve, one tank remains full and is filled automatically if its level changes (Battery) and the other is empty (Capacitor). The...
14. ### Why does a capacitor charge to 63% of the applied voltage?

I am thankful to all the worthy scholars who commented on my question. I become over-enjoyed when people from PF give value to a question, spare their valuable time and add very useful explanations. I can count there are many questions, which I tried hard to find answers with my own effort but...
15. ### Why does a capacitor charge to 63% of the applied voltage?

I am absolutely thankful for your time to address my query. What I meant from my question was how a capacitor knows it should charge to 63% of the equilibrium charge, not 70% or 80% or any other value. Please see the clipping I have attached if my question is still not clear. High regards. Zahid
16. ### Why does a capacitor charge to 63% of the applied voltage?

Statement of problem is given in the summary. Mathematics proves time constant is calculated from the equation V= V0 exp t/RC I want to know if there is any physical explanation of this effect. Please guide me on this. Regards
17. ### Electric Field of a moving charge

Thanks for your time and help.
18. ### Electric Field of a moving charge

Really serious consideration. So matter is not that simple. It involves relativity. Thanks for the time sir. High Regards
19. ### Electric Field of a moving charge

Thank you very much for the reply. I am proud of people at PF for being so helpful in clarifying concepts. What I get out of your explanation is that once charges set into motion, their electric field is mainly canceled out and but just a portion remains due to distortions. But the magnetic...
20. ### Member jim hardy has died

A scholarly homage paid to a noble spirit
21. ### Member jim hardy has died

Wonderful words to pay homage
22. ### Electric Field of a moving charge

Thanks Sir for your effort and time. Mathematics is my downside. I find difficulty in drawing something from these equations. I am apologetic for this weakness of mine.
23. ### Electric Field of a moving charge

Thanks for the time. I ll try the way you suggested. Regards
24. ### Electric Field of a moving charge

Sir, thanks for the reply. Does it have the same intensity?
25. ### Electric Field of a moving charge

When a charge is at rest, it has an electric field only. When the charge starts moving , it is said to have accompanied a magnetic field. My question relates to its electric field while in motion. Does it still exist or not? I know in electron guns electrons are deflected while passing thru the...
26. ### Member jim hardy has died

Very sad demise---- What a nice fellow he was. Just saw his snap and was impressed by his great personality. I wish his soul rest in peace. That is the destiny of all of us. Sooner or later we are bound to die. Let,s spend this time in serving the humanity, respecting each other regardless of...
27. ### Charge on plates in Millikan's Experiment

Thanks dear Sir. The figure you have added has helped me a lot. I ll surely take it down for my class notes. Bundle of thanks for the help.
28. ### Charge on plates in Millikan's Experiment

Thanks for the reply. You meant that general Physics books at secondary level generally miss this explanation for the sake of simplicity. If so, fine. It means plates do have charge left on them if suddenly separated from the battery.
29. ### Charge on plates in Millikan's Experiment

When a capacitor is connected to a battery, it gets charged according to the voltage of the battery. If battery is disconnected, the charge stays on the capacitor. In Millikan's experiment used to find charge on an electron, when two plates are connected to a voltage source, they acquire...
30. ### B Why do metastable states in atoms exist?

Marisa5 Thanks indeed for this further help. This all helped me a lot. Great forum, great people.
31. ### B Why do metastable states in atoms exist?

Thanks indeed. That sound interesting. I need to study it more.
32. ### B Why do metastable states in atoms exist?

Hi My question relates to existence of metastable states in atoms which help out laser production. Is there any physical reason why some orbits allow electrons to stay for comparatively longer time 10-3 s than others which allow only 10-8s? Is this stay time same for all materials? Please guide.
33. ### I Quantities unchanged in Two Inertial frames

Thank you very much all very helpful scholars. After reading all these responses I inwardly realize I need to go through basic lessons of theory of relativity. Would you suggest me some sources where a novice may learn it. High regards.
34. ### I Quantities unchanged in Two Inertial frames

Thanks Sir. You mean the time in one's own frame of reference. I am often confused to understand this term. I apologize.
35. ### I Quantities unchanged in Two Inertial frames

Thanks for the reply. Are there any quantities in 2D or 3D invariant? please mention. Regards
36. ### I Quantities unchanged in Two Inertial frames

But mass increases and time dilates a per special theory of relativity. How are they invariant? please guide. How is acceleration invariant? Please explain. Regards
37. ### I Quantities unchanged in Two Inertial frames

Thanks for the reply. Do you mean both the observers will measure same speed of each other's frame of reference? But speed is length divided by time. If length shrinks and time dilates, should the speed not change? My explanation may reveal my very basic knowledge of relativity. I apologize for it.
38. ### I Quantities unchanged in Two Inertial frames

Thanks indeed to all worthy scholars for their time. I have very basic knowledge of relativity. Understanding 4D analyses seems hard. What if I say in 2D motion if relative motion of the frames is along x-axis, can we say the observers in both frames will agree upon the width (length along...
39. ### I Quantities unchanged in Two Inertial frames

My question is about some physical quantities which two observers in two respective inertial frames will find the same. I wonder are there any such quantities? Some books say force, speed of light etc are constants for both the observers. Please guide me on this. Regards.
40. ### I Hysteresis curve behavior

I tried to but actually the link provided by @Lord Jestocost is too advanced for me. I don't have deep knowledge of this topic.
41. ### I Hysteresis curve behavior

Thanks Sir for the reply. May I know why this happens.
42. ### I Hysteresis curve behavior

Thanks Sir for the reply. Of course B=0 despite the fact domains have different organization. I can guess there is some reason behind two different values of H at the two positions. My really question was to figure out the reasons why domains are not alike. If we take the material out of the...
43. ### I Hysteresis curve behavior

Thanks indeed. I always love to have generic view of laws, applicable to most of the situations. The dimensions you have mentioned, have really opened up my mind to apply this phenomenon in other areas of Physics.
44. ### I Hysteresis curve behavior

Thanks indeed for the prompt reply. I need to go through some attachments which are recommended. Hopefully I will be getting the answer with the courtesy of all scholars of PF. High Regards
45. ### I Hysteresis curve behavior

Thank God, my question is picked. So far I was struggling to clarify what I am asking for.
46. ### I Hysteresis curve behavior

Thanks dear Sir for your time and answer. I d like to argue on this part of your answer. "An 'explanation of why this occurs will be that an increasing H will be doing work on altering the domains and, when H is decreased, work is done by taking Energy from the domains as B reduces." I have no...
47. ### I Hysteresis curve behavior

Thanks for the reply. Yes please explain it with respect to energy consideration.
48. ### I Hysteresis curve behavior

Yes I do. I know domains get fully aligned at saturation point and the material retains it magnetism because the domains don't fully go to complete disorderliness when the current becomes zero. I wonder why my question is not being understood.
49. ### I Hysteresis curve behavior

Thanks Sir for the reply. I can't understand why there are two different values of current to produce the same magnetism. At the start there is higher current needed to cause saturation (path shown as dotted purple in the figure, starting from origin and reaching point a) and afterwards lower...
50. ### I Hysteresis curve behavior

Please help in the explanation of BH curve (See attached file). At the starting point, more current is required to bring the material to its magnetic saturation point( in fig form origin to pt.a shown by purple line ) as compared to when the material is fully demagnetized and then brought to...