Recent content by Blehs

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    Engineering BJT Circuit - Determine region of operation

    Ah ok so when i assumed that conventional current was going OUT OF the base, the results seem to make sense and point towards the BJT being in cut off. However my real concern is - how am i meant to determine that current is in fact going into the base? Was it really just as simple as 1)...
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    Engineering BJT Circuit - Determine region of operation

    Homework Statement See the jpeg image for the circuit. Question is simply determine the region of operation. The Attempt at a Solution The answer is cut off, but i don't really get how it is. Looking at the circuit, emitter voltage Ve should be higher than base voltage Vb...
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    Deflection of electron beam in oscilloscope

    Homework Statement Calculate the deflection of an electron beam as it passes between the plates of a CRT tube. In the picture, the parallel plates create an electric field, with the positive plate on top and the negative plate on bottom, causing the electron's path to be deflected upwards as...
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    Separating capacitor plates: (+) or (-) work?

    woops yeah i was thinking of integration. instead of loged its supposed to be -1/d2 so the two minus signs cancel each other out Got it correct! thnx heaps for clearing things up a little =]
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    Separating capacitor plates: (+) or (-) work?

    Ohhh ok, that makes sense and is simple too - i just thought too much and confused myself i think. Ok so back to the actual question where I am supposed to find F(V). I differentiated U with respect to d and i got dU/dd = (-ϵ0AV2/2) x loged so does F(V) = dU/dd?
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    Separating capacitor plates: (+) or (-) work?

    No i had to work out the function for U myself. It was an earlier part of the hint so i just chucked the equation in. Ok well starting from the equation F = -dU/dd, i thought that in general, dU would mean change in energy (like u2-u1) and dd means change in distance (d2-d1). Therefore the...
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    Separating capacitor plates: (+) or (-) work?

    Homework Statement Consider a parallel-plate capacitor with plates of area A and with separation d. Find F(V), the magnitude of the force each plate experiences due to the other plate as a function of V, the potential drop across the capacitor. Hint i used If the plate separation were changed...
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    Electric field in electrostatic situation

    AHA YES I GOT IT RIGHT WOOOOOOOOT Thnx heaps DiracRules
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    Electric field in electrostatic situation

    Ok so when you say solve the inequality, I am guessing you mean try the conditions where q1>q2 and q1<q2 and see if the value still lies within zero and "s". So first i started off with the - solution which is s(q1 - root[q1q2]) / (q1 - q2) For the q1 > q2 condition i found using...
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    Electric field in electrostatic situation

    The entire question is posted above. I forgot to add this in before, but i opened up a hint on "solving the quadratic and choosing the correct answer" "If you set the magnitudes of the fields due to q1 and q2 equal at point P, you should end up with a quadratic equation for x. This equation...
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    Electric field in electrostatic situation

    Homework Statement Two particles with positive charges q1 and q2 are separated by a distance s. Along the line connecting the two charges, at what distance from the charge q1 is the total electric field from the two charges zero? Homework Equations E = kq/r2 where k = 1/(4 x pi x...
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    Engineering First order circuit with DC sources

    WOW that clears up so much. Alright i get it now =] Thnx heaps for the help, will be useful for my upcoming exam in 2 days time =P
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    Engineering First order circuit with DC sources

    I learned that when current reaches a crossroads, then the current likes to choose the path with less resistance. Since the wire is practically at zero resistance then wouldn't all current flow through the short circuit instead?
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    Engineering First order circuit with DC sources

    Ok so BEFORE the circuit is redrawn, and there's just a single wire with no resistor on it connecting a and a' - if you were to trace the current from the 12A source wouldn't the current simply bypass the 9 ohm resistor and go through the short circuit all the way to a'? Then the current would...
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    Engineering First order circuit with DC sources

    The circuit is in the attachment, plus the values that I've managed to find out so far. Im having problem with figuring out the voltage at t=infinity. So far i know that when t->infinity that inductors become short circuit. It says to apply current division and then Ohm's Law as a hint, and...
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