Conduction Definition and 423 Threads

Can anybody explain to me why holes are found at the top of the valence band, whereas electrons are found at the bottom of the conduction band.

A thermal window with an area of 6.00 m2 is constructed of two layers of glass, each 4.00 mm thick and separated from each other by an air space of 3.00 mm. If the inside is at 20.0°C and the outside is at -38.0°C, what is the rate of energy transfer by conduction through the window? i am...

I have been reading a number of aerodynamic texts, and it seems that everything in a fluid (gas) is transmitted by molecular collisions. Pressure is a result of molecules colliding with each other and the walls of a container Viscosity is caused by collisions between molecules in layers...

I am trying to find a way to calculate the Ec for intrinsic silicon at room temperature. I can't seem to find anything in my textbook for that. I have searched on line and the closest thing I can find is E_c = E_g + \frac {\hbar^2 k^2}{2m_e} I know what Eg = 1.12 eV for intrinsic silicon at...

I read on Wikipedia: Is myelinated interneurons redundant? If not, why? What's being done about getting this stuff into human brains? How is this myelin different? - Wah! mk.

I'm having difficulty figuring out how to work this problem: Assume a material has a given E-K diagram: E(K)conduction = Ec + E1 * sin^2 (Ka) E(K)valence = Ev - E2 * sin^2 (Ka) a=0.5nm E1 = 5eV E2 = 4eV I have to: * sketch the E-K diagram for the first brillouin zone (-pi/a < k <...

Given the 3-D rectangular solid with sides of length a, b and c in the x, y and z direction respectively. Find T(x,y,z) in the interior of the solid when laplace T = 0 Boundary condition are following conditions: 1) x=0, T=0 2) x=a, dT/dx=0 3) y=0, dT/dy=0 4) y=b, dT/dy=0 5) z=0, T=0 6)...

Anyone please explain to me what is conduction band and what are conduction band electrons? What energy do they have and how do they transfer it?

A styrofoam cooler (K = .030 W/mo C) has an average surface area of 0.465 m2 and an average thickness of 2.0 cm. About how long, in seconds will it take for 4.10 kg of ice at 0oC to melt in the cooler if the outside temperature is 28.0oC? delta Q/delta t = (k*A*deltaT)/d delta Q = 333 J/g...

hey, can anyone help me with this question? I am really having trouble with it. 1. Two metal rods, one lead the other copper, are connected in series (end-to-end). Note that each rod is 0.525m in length and has a square cross section 1.5cm on a side. The temperature at the lead end of the...

Could anyone help me solve the following problem? Calculate the ratio of the conduction current density to the displacement current density of the electric field E = E_0 \cos(\omega t) in copper, to a frequence of f = 1 kHz. (Given: \epsilon_{Cu} = \epsilon_0, \rho_{Cu} = 2 \times 10^{-8}...

Hi; Could somebody please help me with the following question: During the action potential, Na+ ions move into the cell at a rate of 3.03E-7 mol/m^2*s. How much power must be produced by the "active Na+ pumping" system to produce this flow agaisnt a +33.9 mV potential difference? Assume that...

Approximately how long should it take 8.78 kg of ice at 0oC to melt when it is placed in a carefully sealed Styrofoam icebox of dimensions 27.2 cm x 35.7 cm x 51.2 cm whose walls are 1.20 cm thick? Assume that the conductivity of Styrofoam is double that of air and that the outside temperature...

I'm doing a projekt on heat conduction i a box. The point is to simulate a house very simple. We have time varying temperature conditions on the outside, and want to model the temperature inside the box over time as outside temperature changes. The box will consist og an outer wall, insulation...

Apparently my lecturer has given me this type of quest and i really have no idea how to do this quest..anyone know the formula for conduction current..displacement current and loss tangent..please give me brief idea how to do it...what i know is that for displacement current i have to...

Hello friends I have a problem and also know its answer but I have some trouble figuring it out. Here goes Two vessels filled with different liquids are at temperatures T_{1} and T_{2} respectively. They are joined by a metal rod of length l; area of cross-section A and thermal...

figure show 2 ways how 2 thin nichrome wires P and Q at fixed p.d. V are connected. Both P and Q are of the same length but the diameter of wire P is bigger than that of wire Q. When wire P and Q glow steadily in both circuit, which on of the following shows the comparison of brightness between...

Hey - do you think anyone could help explaining the process of conduction and radiation, convection currents for me? Physics exam next Monday, and I have to start studying soon! Also, what is density measured in? Kg/M^2? Thanks in advance!

I am working on a project that requires me to calculate the heat dissipation of a heatsink attached the a laser optic mirror. As the whole system is moving along a rail at 10m/s (average, 20m/s at fastest point) therefore forced convection takes place on the heatsink surface. I have modeled the...

Hi, these two questions have been boggling me for a week.. if anyone can I help I'd be very appreciative. The first one is.. A cylindrical rod of length 1.5 m and radius 0.02 m is insulated to prevent heat loss through its curved surface. One end is attached to a thermal reservoir at 573...

How can I calculate BTU value generated from 1 inch copper pipe with the length of 1 foot through which 176F hot water is passing?

When Maxwell showed that light was an electromagnetic wave it was necessary to identify some oscillator of atomic proportions to account for these waves. Henri Lorentz , considered that electrons which are normally held in an equilibrium position are capable of vibration when displaced under...

I thought the thing that makes a metal more conductive is the number of free electrons... How then is copper more conductive than iron when copper has only 8.47 (x10^22) free electrons per cm cubed compared to a massive 17 for iron? If someone could explain this to me my face will go like...