Recent content by Myrddin

Derive the relation Δn.Δσ ≥ 1/2 where n is number of photons in an EM field and σ is phase Using heisenburgs uncetertainty principle? Tried subbing in frequency into heisenburgs uncertainty principle to get to the number of photons and to get rid of mometum is this the right line? Dont...

so just about finishing a report on x ray abosprtion on different materials, generally the linear attneuation coefficient increases with atominc number Z. However silver(47) had a lower attenuation coefficient then zirconium(40) despite having the significantly higher value of Z. With some...

An inflated smooth toy balloon is coated with a single atomic layer of aluminium. Esitimate the mass of Al that would be required. The density of Al is 2.7 x10^3kg/m^3 and its molar mass if 27 grams for mol. I assusmed the balloon was a sphere of radius 10cm, found surface area then...

Anti clock wise moment should equal, dR2sin(theta)? so ---> dMmgsin(theta) this gives anticlock wise = clockwise So dMmgsin(theta) = xmgcos(theta) so x = dMmgsin(theta) / mgcos(theta) = dMtan (theta)?

Ladder Problem (urgent) A light of negligible mass and length d is supported on a rough floor and leans against a smooth vertical wall makeing an angle (theta) with the floor. The coefficient of friction between the ladder and floor is M. If a painter climbs the ladder up distance x, what...

For the first question is it just showing the relation ship for any negative feed back op amp circuit, like Vout/ Vin = - R2 /R1 for inverting op amp, for this to be so inputs must equal one another. Dont know what it means by time dependent tho? Q / Qmax = [1 - exp(t / RC] formula to find time...

http://img707.imageshack.us/i/electronicsoscillator.jpg/ Dont know where to start for showing voltage difference at input is zero, suspose its something to do with non idealities of the op amp? For the oscillator question , kinda know how its works; there's positive saturation giving...

Figured out part b) and c), its to counter input bias current and R = 1/R1 + 1/R2

Inverting amplifer question http://img210.imageshack.us/i/electronicsquestionsq30.jpg/ Can do part a) ! Vout/ Vin = -R2 / R1 and found part d) in a book, that closed loop gain is less but more linear and am able to draw the graph. Any help with b) c) e) f) would be great, particulary...

Thats the whole question. I see there's a potential divider to find the values of resistance for Rb1 and Rb2, what i don't know know is what it means to "bias the amplifier". I am very unfamiliar with transistor circuits know only the very basics, the collector the base the emittor. Know that...

Doing practice exam papers for electronics module, can someone explain to me how to go about this question? http://img402.imageshack.us/i/electronicsquestions.jpg/

Seem as though there's no acousticians in the house !

Have worked on part 1) and 2) hopefully enough for the project, going to do detail of how our results of damping are shown in use of special materials in theatres and qudiotoriums etc, and talk about musical instruments for 2). Any help with 3) would still be grateful as the material I am...

still not done !

Have a project to do on an acoustic resonance chamber, a loudspeaker attached to a perspex box with a copper pipe, there was a microppohne inside the chamber connected to oscillloscope. We investigating a few variables in most detail was route [1] [1]damping by chainging materials in the...