2074 Chaitra Regular
2074 Chaitra Regular electrical Engineering Material IOE Pulchowk
1. a) Calculate the temperature at which there is 98% the probability that a state 0.3 eV below the Fermi energy level will be occupied
by an electron.[4]
b) Prove that the energy of a particle confined in an infinite potential well is quantized. Also, find the expression for the normalized wave function.[8]
2. a) Draw face-centered cubic (FCC) unit cell and find body diagonal and packing density.[6]
b) The conductivity and drift mobility of copper conductor is 63.5*100 s/m and 43 cm/v/s. Calculate the Fermi level for the copper conductor.[4]
3. a) Show that the dielectric loss per unit volume is a function of the frequency of the applied field and the loss tangent.[6]
b) What do you mean by piezoelectric materials? Explain the piezoelectric effect in terms of polarization.[4]
4. a) On the basis of the magnetic vector, explain the ferromagnetism, ferrimagnetism, and antiferromagnetism.[6]
b) What is the Meissner effect? Explain the difference between type I and type II superconductors. Type II superconductor is also called hard superconductor, why? [8]
5. a) Differentiate between non-degenerate and degenerate semiconductors.[6]
b) What are the Built-in potential and depletion width? Derive the expression of these with necessary diagrams.[6]
c) Calculate the resistance of pure silicon cubic crystal of 1 cm at room temperature. What will be the resistance of the cube when it is doped with 1 arsenic in 10 silicon atoms and I boron atom per billion silicon atoms? Atomic concentration of silicon is 510% cm ni = 145.10cm-3.[8]
6 a) Calculate the diffusion coefficient of electrons at 300K in n-type silicon semiconductor Also find the current density of electron concentration gradient is 10 electrons per centimeter.[4]
b) Obtain the expression to evaluate the built-in potential and width of the depletion layer of pn-junction with necessary diagrams.[10]
b) Prove that the energy of a particle confined in an infinite potential well is quantized. Also, find the expression for the normalized wave function.[8]
2. a) Draw face-centered cubic (FCC) unit cell and find body diagonal and packing density.[6]
b) The conductivity and drift mobility of copper conductor is 63.5*100 s/m and 43 cm/v/s. Calculate the Fermi level for the copper conductor.[4]
3. a) Show that the dielectric loss per unit volume is a function of the frequency of the applied field and the loss tangent.[6]
b) What do you mean by piezoelectric materials? Explain the piezoelectric effect in terms of polarization.[4]
4. a) On the basis of the magnetic vector, explain the ferromagnetism, ferrimagnetism, and antiferromagnetism.[6]
b) What is the Meissner effect? Explain the difference between type I and type II superconductors. Type II superconductor is also called hard superconductor, why? [8]
5. a) Differentiate between non-degenerate and degenerate semiconductors.[6]
b) What are the Built-in potential and depletion width? Derive the expression of these with necessary diagrams.[6]
c) Calculate the resistance of pure silicon cubic crystal of 1 cm at room temperature. What will be the resistance of the cube when it is doped with 1 arsenic in 10 silicon atoms and I boron atom per billion silicon atoms? Atomic concentration of silicon is 510% cm ni = 145.10cm-3.[8]
6 a) Calculate the diffusion coefficient of electrons at 300K in n-type silicon semiconductor Also find the current density of electron concentration gradient is 10 electrons per centimeter.[4]
b) Obtain the expression to evaluate the built-in potential and width of the depletion layer of pn-junction with necessary diagrams.[10]
0 Comments:
Post a Comment
Please don't enter any spam link in the comment box