4. What is the primary driver of thermal conduction in semiconductors? a) Phonons b) Electronic excitation...
[SA: 3 marks] For 2-D conduction, the thermal resistance is A) (Sk) B) L(ka) C) In ( ) + (2 KL) D) R..come + A E) 0 F) kA(L)"
of a) What are the sources of losses for semiconductors devices? (2 Marks) b) A thyristor with a steady power loss of 300 has a junction to heatsink thermal resistance of 0.7°C/W. Determine the maximum value of the thermal resistance the heatsink can have if the ambient temperature is or and the junction temperature is limited to 125 C. Give the heatsink femperature at these conditions. Marks) c) The thyristor in the switching circuit of following figure has rating of...
What is the primary driver of business cycles according to monetary theory? a. credit cards b. fluctuations in the supply of money in the economy c. aggregate decisions over saving and spending d. supply of money
PLEASE ANSWER a,b,c Heat Conduction Heat conduction occurs through any material, represented here by a rectangular bar, whether window glass or walrus blubber. The temperature of the material is T2 on the left and T1 on the right, where T2 is greater than T1. The rate of heat transfer by conduction is directly proportional to the surface area A, the temperature difference T2 - T1, and the substance's conductivity k. The rate of heat transfer is inversely proportional to the...
Q6. [20 Marks] (a) Write short notes on electrical insulators, conductors, and semiconductors (3mrk) (b) Write notes on intrinsic and extrinsic semiconductors (3mrk) (c) Define the terms valence band, conduction band and forbidden gap (3mrk) (d) Describe in brief, the Band theory of formation of energy bands in solids (4mrk) (e) (i) Explain what is meant by Density of States (DOS) (1mrk) The density of states function for electrons in a metal is given by: Z(E)dE = 13.6x1027 E2 DE...
Consider the statements I and II below given about semiconductors: I. Doping Si with P creates free electrons. II. Doping Si with B creates holes. Which of the following statements is/are correct? A. Only I B. Only II C. Both I and II D. Neither I nor II
A3. (a) According to Fourier's Law of thermal conduction, the heat flux through a solid is given by the solid's thermal conductivity k multiplied by the negative of the local temperature gradient. If the temperature in the solid is given by the function T(x, y, z)= 30e **(y2 + z), determine an expression for the heat flux through an internal surface with normal n=2i+j+2k [7 marks) (b) If f(t)=3sin ox and g(t)= 2 cos(@t++), determine the amplitude of the function...
(19. A primary driver of overhead costs in continuous manufacturing operations is: A) direct labor dollars. B) direct labor hours. C) machine hours. D) machine maintenance dollars.
4.6 A,b,c,d distribution at the same teiiper atul 4.6 Electrons in semiconductors. A semiconductor has a p efective m 2x 1028 m 13 Phonon sp relation (th structure h2 The Fermi level in the semiconductor could be above or below the conduction band edge. Take the electron effective mass as the free electron mass. For Ec 0.05 eV and T = 300 K, do the following in the range 0.0 eV < E-E 0.1eV: where a is Derive an e...
17. The distance between an electron and a hole across a band gap following electronic excitation is called A. Bohr exciton radius B. Bohr radius C. quantum D. conduction band 18. When a photon strikes an atom, the energy is absorbed by A. a proton which moves to an excited state. B. a neutron which causes the nucleus to split. C. an electron which moves from the ground to an excited state. D. nothing. A photon is never absorbed by...