Recent content by chitrageetam

Can anybody give a rough estimate of price for a chemical Vapour deposition equipment to make carbon nano tubes? How much budget do we need to establish a laboratory to make carbon nano tubes?

Hi Toli Thanks but.. this formula does not account for eddy current / induction heating due to the high frequency. If we have to use RMS value, then heating for 1kHz will be same as heating for 5 kHz..which is not true in reality..higher frequency gets it more hot. I think the formula must be...

Hi Heat generated by the conductor because of DC is i*i*R where i is the current and R is the resistance. Does anybody know the heat generated by the same conductor for an AC? For example frequency 5kHz, DC resistance-20 ohms, RMS current is 3A.. How do we calculate this? I do not...

Thanks for your replies Palladin and Phrak, the explanation seems more fit for eddy current losses than for skin effect losses.. Another thing is I am not able to believe..the line.. "there is a delay in the magnetic field's response to the change in current".. I have been in an impression that...

Can anybody explain the skin effect more clearly- why does the current tries to concentrate more closely to the surface of the conductor at high frequencies? what is happpening inside the conductor? thanks

Dear Fred Thank you for your reply. So..It means when we pluck and leave a beam, its vibrates at its modes of natural frequency.. did i get it right? If we pluck a beam having 1, 3, and 8 kHz as its first three modes, in its FFT, we get three peaks at those frequencies..provided we sense if...

Hi.. I have a question about natural fvibration. Every object has natural frequency and modes of vibration. Let us consider a simple cantilever beam for our discussion. and Let's say its first 4 modes of vibration are at 3, 6, 10 and 20 kHz respectively. (I made up these frequency values)...

1.2 GPa? Thanks for your information.

Hi.. Anybody knows the Elastic modulus of crazy glue? Thanks

hi Bob.. Did you say that you want to switch the direction in milliseconds,..meaning kHz? Okay, if you use DC switching, it will be like a sqaure wave rather than a sine wave..isnt it? It will not ramp up or ramp down. Well, even before conducting the experiment, do you have theoretical...

Mr.Bob.. Thanks for reply.. I mentioned the coil size not as a suggestion to your task but only to understand the problem ..."weather the field in AC coil is same as DC coil?" Did you ever notice any drop in field with the increase in frequency, with same current? Thanks

the way i am driving is .. connect command signal to car audio amplifier, and connect the coil to the coil.. V and current are measured using 2 34401As.. and magnetic field is measured by bell gaussmeter..which can go upto 12 kHz with with error within 6%. ..does capacitance between the coil...

For DC input, I derived the equation to tell the field along the axis of the coil. How can I modify that for an AC? Lets say, the coil is of length 2L..-L to +L. Does H at +L or -L same for both AC(rms) and DC of same current? If different, By what factor is AC field lesser? Thanks

Thank you f95toli, My multimeter is HP make 34401A.. its decent peice. R of the coil is 1 ohm and L is around 0.25 milli henry. The measurements at 100 Hz are at good agreement with estimated but those at 10 kHz vary by 50%. thanks for your input Chitra

Hi .. I have posted another question on AC coil before seeing this post. My question was... What happens to the magnetic field in a solenoid coil when the frequency is increased, and by keeping the current constant? As per my idea, The field must remain constant as the current is constant...