# Search results

1. ### Lift a weight up with an EM switch

Hello, My question is simple. Let's suppose you have an electromagnetic coil with a magnetic weight in the center of it. This coil is energized, and the weight is lifted up vertically. Now, my weight is 30 kgs. I want to lift it to a height of 1 meter. How do I calculate how much power is...
2. ### What happens when an electron is hit by a laser beam?

Light sails use mirrors, I was aware of them before. But I am specifically asking what direction an electron would be scattered in, in the presence of a laser. Can a laser be used to guide an electron for instance? Or does the scattering take place in all angles?
3. ### What happens when an electron is hit by a laser beam?

Just a quick question. We know that an accelerated electron shoots out light, and light that falls on an electron in an atom, excites it. But what happens to an electron in vaccum, when it encounters a laser beam? If an electron beam from an electron microscope, were to to intercept a laser...
4. ### Does light affect the magnetization of a material?

My question is really basic, and I've ended up getting a bit confused because of it. My understanding is that magnetism of a material is based upon the intrinsic electron spin, the rotation of the electron around an atom, and the movement of electrons within a material, i.e- current. So...
5. ### Maximum distance of quantum tunneling using an STM

Okay. That's brilliant. Thanks a lot soothsayer. You've been a great help. Kudos to you. :)
6. ### Maximum distance of quantum tunneling using an STM

Hey! Thanks for the replies, you two. But the thing is, the image resolution is not so important for me here. The purpose for which I aim to use the STM in this instance, doesn't demand that. All I need is a tunneling current from the tip of my STM and a metallic conductor that is separated by...
7. ### Maximum distance of quantum tunneling using an STM

Hey there, I'm pursuing a degree in Msc. Nanoscale science, and I've been studying about Scanning tunneling microsopes that use Quantum tunneling to study the surface struture of materials. My question is: What is the maximum distance between the surface that's been studied, and the STM tip...
8. ### Master in Physics vs. Bachelors in Engineering?

First of all, is a course in Nanotechnology or Nanoscience worth it or is it just a lot of hype? What can I do after a masters in Nanotech/science? Is it better to do it in UK or in USA? USA has only two colleges that offer this course, namely Rice and SUNY-Albany. But, there are a lot...
9. ### Any published authors here?

ah.. okay... cool... :smile:
10. ### A really basic question.

k... will put it on my list. :smile:
11. ### Amplitude of Electromagnetic wave?

How come the energy of an electromagnetic wave depends only on its frequency? Given by E = hf. How come the energy depends only on the frequency of the wave and not on the magnitude of the E component of the wave? Doesn't the energy depend on the amplitude? Or is there no such thing?
12. ### Any published authors here?

Nah, it is not about the Idea itself. Its just a fun read. Anyway, I was asking about query letter tips and the like. For example, check this site out: http://www.indiahowto.com/list-of-publishers.html anyway... thx. Let's see how it goes.
13. ### A really basic question.

Hmmm... that is a good Idea. Ill try ignoring the equations. I am not going to study physics in coll anyway. I just have an interest. Anyway... thanks...:approve:
14. ### Any published authors here?

ha, lol. That I know, I am fully aware of vanity publishers. And naw, its nothing about physics at all. Its just story about a guy who just gets out of college and tries an Idea about some software. He then realizes that things are not that easy and basically what happens after that. Its a...
15. ### A really basic question.

Hmmm... Well, I did read the brief history of time. It was interesting, but it didn't seem tough. But I guess as ZZ said, only someone who knows physics would be able to understand why its tough. I have a long way to go. Consequently, I got the Feynman series of lecture books and although...
16. ### Any published authors here?

Ah, yeah... Its pretty simple overseas. But there are a few reputable publishers in India. Its not the same thing. I have been to many sites, I just thought there maybe someone here.
17. ### A really basic question.

Hmmmm... I suppose a deeper understanding of QM is required before I understand. Okay, thank you, I will read on, on my own. Someday, the quantum weirdness is bound to seep in... :biggrin:
18. ### Any published authors here?

Hey, Anyone here have any experience with publishing books? I wrote a book and am trying to get it published. Any Tips / tricks on how to go about the thing? :wink:
19. ### A really basic question.

Hmmm, well that just puts more questions in my head. Is there an explanation of what set about this orbiting in the first place. As far as I have read here and there, the reason the planets move in a curved path is because the Huge mass of the sun curves space - time and hence even though...
20. ### A really basic question.

I doubt that its the same thing. The moon hovers above the Earth only because the Earth is in constant motion. Its sort of like a dance that they do, the Earth pulling on the moon, the moon pulling on the Earth and they both in turn being pulled by the sun. But, that's not the case with the...
21. ### A really basic question.

Okay, thanks, I did. That cleared up a lot of things. But, I am assuming smeared means you plot the probability of the particle in an area where it is most probable to occur. So, is the electron around the nucleus or is it attached to it? And if it hovers above the nucleus, what forces...
22. ### A really basic question.

This is a really basic question but, why are the electrons revolving around the nucleus, why not just stick to the protons in the nucleus? And since, the electrons repel, it would explain the reason for the space between the atoms right? Anyway an atom is electrically neutral, so that also...
23. ### An electromangetic switch

I have attached a diagram and no this is not a commercial product, a friend of mine made this. The diagram is a sketch of the system.
24. ### An electromangetic switch

So, I have an electromagnetic switch. Which works in this way. A rod has 4 magnets attached to the front of it and 4 magnets attached to the back of it. In the center there is the winding. When I apply current to it, the rod moves towards one end and hits a steel plating on that side fixing...
25. ### Do we also travel at a fixed velocity?

Thank you for your replies, So, the way I understand what you people have said so far is this: 1) All velocity is judged from an initial rest frame. 2) Light has no initial rest frame, so judging velocity from its perspective is meaningless. Okay... this is just like another one of...
26. ### Do we also travel at a fixed velocity?

Since, light is always traveling at a constant velocity with respect to everything else, does it also mean that everything else is also traveling at a constant velocity with light? As in, since light is always traveling at C irrespective of our velocity, then does it not also mean that we are...
27. ### IQ Tests: PF Members Weigh In

The whole concept of intelligence is highly overrated as far as I can tell. I would consider someone intelligent if they can put two and two together, as in, if they can say okay, take chocolate cake and vanilla ice cream... Now if we put it together then it would taste much better... That is...
28. ### Reactance is equal

Now if we take the impedence for a circuit. Xc for the capacitive component and Xl for the inductive component and equate them, that is we equate the impedance then we can get the same impedance from both a capacitive as well as a inductive load, we get something like this. Now, in...
29. ### Zeitgeist the movie, Real? or just Real crap?

Zeitgeist the movie, I watched a downloaded version of it. It can be seen online for those who haven't at this site, http://www.zeitgeistmovie.com/ Its an awesome movie and if its true, its a real eye opener, if its not... Man, I sure got fooled... XD Now some people claim that its...
30. ### What happened to PF chess?

Its been quite sometime now since, pf chess has disappeared... I thought it would come back after sometime... but no... So... what happened to it?
31. ### Magnetic field in a semi-cut solenoid

Im just curious as to how the magnetic field would be for a semi cut solenoid as shown in the diagram below. The Solenoid covering is partially cut and the soft core iron in the solenoid is also cut and the number of windings in the area decrease considerbly.. The winding on either side...
32. ### Effeciency of regenerative braking

I am just curious, but what is the average efficiency of Regenerative braking? As in... How much of the kinetic energy are they able to convert back to electrical?
33. ### How did you come up with your username?

the_thinker cause I would like people to believe that I actually do think, even though its a rare occasion, it happens sometimes... :tongue:
34. ### Are you single, married, or do you have a gf/bf?

Ah, well... Being single is fun, I am very happy, I am looking for just this one girl, she should be a lot like me and that's a bit difficult to find, I really believe that there's someone out there who perfectly match with each other, there are after all, so many people... But the problem is by...
35. ### Inside A RAM card

yeah... exactly... Not flash cards, RAM cards, the ones that you insert into the DIMM slots of your motherboard, the volatile ones..
36. ### Inside A RAM card

Hey, I am interested in knowing about the insides of a RAM card. I want to know what type of capacitors they use in RAM cards, how are they made and what is the maximum capacitance of these capacitors?... Also what type of transistors they use in the memory cells. How is the data read? I...
37. ### Bistatic radar

Hey... Why don't you be a little more specific... your being a bit general... As in.. what area are you finding a problem in?
38. ### PF Member Photo Thread Archive

This is me... By the way... is the contest thing still on?
39. ### A few questions about magnets

Just a few simple questions about magnets: 1) If 2 permanent magnets are placed one on top of the other such that one magnet repels the other and therefore the second magnet levitates and assuming that this is a ideal situation and the magnet is not knocked off its vertical levitating...
40. ### How does BPL work?

1)Broadband over power lines... How do they work? and how can they provide such high data transmission rates compared to DSL and other network architectures? How is it that they do not interfere with other electrical appliances in the home like fans and switches? I mean don't they offer a...
41. ### I want to fabricate a pn junction

Any idea where I can fabricate a p-n junction of a custom length? I want it to be of a particular length and size, any company that can do it for me? How costly would it be?
42. ### How come no interferance takes place

ah... so, in for say very short distances with little interference in the transmission line your telling me that analog signals can be actually faster? hmmm... could you tell what type of modulation scheme allows this?
43. ### How come no interferance takes place

ah... okay... that's what I was wondering... it clears things up... But nowadays they don't use analog signals anymore right? And yeah... I know about PWM So... What did you mean by...Usually you can't send a high data rate this way but it's useful for adding a new data layer onto an...
44. ### How come no interferance takes place

Okay... I think I get it, its like using superimposing a carrier signal onto a message signal, when you superimpose a lot of frequencies together, you get the resultant output signal, but does this apply to even digital signals? The way I understand it, does this superimposing apply only to...
45. ### How come no interferance takes place

ah... okay... right, so Em waves don't interfere much? I did not know that... that clears up a lot... Okay forget EM waves, let's say you take a transmission of signals through a link between 2 computers... In like a DSL connection... I have read that it cuts up normal telephone line into...
46. ### How come no interferance takes place

If 2 signals of different frequencies are sent through the same medium... let's say 2 rf signals are sent through the air at the same time of different frequencies, how is one able to receive the signal at the other end? I mean even though the receivers are tuned to the frequencies at the other...
47. ### Output power of a microphone?

hmmmm... first of all... thanks for replying mate... Okay... If I used a piezoelectric microphone, how many millivolts would that produce? around let's say... .2 volts or around 200 millivolts?? Is that value too high?? Also how much would one cost? and ah... okay.. thanks for clearing up...
48. ### Output power of a microphone?

1)right...well, a microphone converts audio signals into corresponding electrical impulses right.. I just want to know how much is the average output power of these things? and how much voltage can be achieved from them... 2)Another question I have is, what kind of antenna do they use in a...
49. ### Why can't a constant electric field be used for transmission of signl?

yeah, see... all I was trying to say is that, one there's a difference between a 0 signal and a constant signal, second its okay to use the water analogy to the rf signals being generated, but both are not the same phenomena- first of all, the water waves are not a fundamental effect of...
50. ### Add a wind turbine to a car?

yeah... that's what I felt too actually... it could be done.. but it would be less efficient, so its a non-gain project... thanks for the replies guys...