Recent content by bennyq

Homework Statement I was to calculate the Fermi Wave Vector $K_F$ for a metallic structure then explain why the nearly free elctron model is consistent with its behaviour?The Attempt at a Solution After calculating the wave vector, I see that the fermi wave vector is within an energy band...

Homework Statement Calculate the de Broglie wavelengths of an electron with energy 120 eV ...Homework Equations lambda = h\p where p = sqrt(2*Me*E) The Attempt at a Solution E=1.6E-19*120ev.. Then sub into equation and I get 1.1E-10m for the wavelength, which is the answer quoted. The...

Homework Statement A current-carrying ohmic metal wire has a cross-sectional area that gradually becomes smaller from one end of the wire to the other. How does the current vary along the length of the wire? Homework Equations a. It increases. b. It remains constant. c. It...

Homework Statement A coil with zero resistance has its ends labelled a and b. When a current is passed through the coil the potential at a is higher than the potential at b. Which of the following would be consistent with this situation? (Note, there may be more than one correct alternative.)...

Ahhh i see, yes thankyou

Homework Statement In Niels Bohr's 1913 model of the hydrogen atom, an electron circles the proton at a distance of 5.29 E-11 m with a speed of 2.19E6 m/s. Compute the magnitude of the magnetic field this motion produces at the location of the proton.Homework Equations ∫B.ds = μIThe Attempt at...

I think i worked this one out, when they are connected by the wire the potentials are equal so V1=V2, simplifys to \frac{Q1}{Q2}=\frac{r1}{r2}=\frac{σ2}{σ1} Leading to the correct answer..

KVL in the loop, starting at 3.. 3->2 -3v(rise) 2->1 -5v(fall) 1->4 -9v(fall) 4->3 17V(rise) -3-5-9+17=0, so the voltage in the loop adds up. Now from V3->V2->V1 V3-3-5=0 V3=8V Now from V3->V4->V1 V3-17+9=0 V3=8V Seems okay to me?

Firstly, there is only two essential nodes, so once you set node (M,N) to ground that leaves node B as the only other essential node. This means you only need to write ONE KCL equation to solve for one unknown nodal voltage. I think the problem you have here is that you need to write KVL...

Homework Statement A metallic sphere A of radius 1.00 cm is several centimetres away from a metallic spherical shell B of radius 2.00 cm. Charge 450 nC is placed on A, with no charge on B or anywhere nearby. Next, the two objects are joined by a long, thin, metallic wire, and finally the...

Homework Statement Which one of the following statements concerning electrostatic situations is false? a) No work is required to move a charge along an equipotential surface. b) If the electric potential with a region of space is zero volts, the electric field within that region must also be...

Just a question if you had to write a boolean expression for a problem like this, A motor requires three conditons ABC to be high to start, but a manual override can start and stop it (M) what is the expression for Z so Z = ABC... how would you incorporate the overside switch.

ah okay, thank you chet

in my sketch, i have Pa = LHS p(oil)gh = RHS p(water)gL .. g cancels our but i have two unknowns..which is the different heights of each column?

Homework Statement One hundred millilitres of water is poured into a U-tube that has a cross-sectional area of 1 cm2. Then 100 millilitres of oil, with a density 80% that of water, is poured down one side of the U-tube so that the oil floats on the water. Find the difference in height of the...