Recent content by carnot cycle

Homework Statement The threshold voltage (Vtp) of this p-channel transistor is -0.4V. Determine the region of operation of this transistor. Homework Equations Vsg + Vtp = Vsd(sat) The Attempt at a Solution Since the gate-source voltage is 0V, and the threshold voltage is...

Young Freedman University Physics The textbook uses a wire connected to a parallel plate capacitor in order to derive the formula for displacement current. C = capacitance, Q = charge, V = voltage applied CV = Q. Voltage = Ed, where d = distance between plates, since E (the electric field)...

Homework Statement I am having trouble grasping why exactly displacement current and conduction current are sometimes equal to each other and sometimes are not. My textbook states that the displacement current is defined as ε0 * d(EA)/dt. That is, epsilon not times change in electric flux. I...

Homework Statement Find the total magnetic force on the semi-circular part of the conductor. There is a current I running counterclockwise through the semi-circle. The magnetic field B is out of the page.Homework Equations F = Il x B l = Rθ dl = RdθThe Attempt at a Solution I assumed that the...

Well just when I thought I understood these types of problems, I came across one that has left me confused for a while :( The textbook states that when the switch is closed, the two capacitors shown are connected in parallel. However, I don't understand why they are connected in parallel, and...

Thanks everyone for the help! I've tried a few more problems and seem to be able to solve them now.

So does this mean that the two C1 capacitors between nodes A and C are also in parallel?

Yes I see that, but why is it not also parallel to the left most C2 capacitor? EDIT: Also, how did you know to place the C1/3 equivalent capacitor such that it is parallel to the C2?

Homework Statement Compute the equivalent capacitance for the network between points A and B.Homework Equations 1/(Ceq) = 1/C1 + 1/C2 + 1/C3... (series) Ceq = C1 + C2 + C3... (parallel) C1 = 6.9 nF C2 = 4.6 nF The Attempt at a Solution I have been getting stuck on a lot of these questions. A...

Yeah when I plug in -10V for Vr I do get the correct answer, 2.90 cm. However, how can there be a negative potential from a positively charged cylinder? Or does the -10V just mean that the potential at 2.90 cm is 10 volts lower than at the surface of the cylinder? Thanks for the help :)

Where am I missing a negative sign?

Homework Statement A very long cylinder of radius 2.00 cm has a uniform charge density of 1.50 nC/m. Taking the reference level for the zero of potential to be the surface of the cylinder, find the radius of equipotential surfaces having potentials of 10.0 V, 20.0 V, and 30.0 V. Homework...

Ohhhh okay, now I see where I went wrong. Thanks so much for helping!

So the force from the -e charge is ke^2/4a^2 and the force from the +e charge is ke^2 /a^2? and I subtract these two to find that the net force is 3ke^2/4a^2, which I integrate from x= infinity to x = 2a? If so, then i performed these steps in post 6 but did not retrieve the right answer.

But don't both charges create a net force that pushes q3 from x = 2a to x = infinity? So shouldn't the limits of integration be infinity to 2a? Sorry that I keep asking the same question. I just can't conceptually grasp it