ASSIGNEMENT 1 Electronics Principles: ELPH501 Part A: Electronic circuits Question 1. [10 Marks] A combination circuit is shown in the diagram at the right. Use the diagram to answer the following questions. a. The current at location A is _____ (greater than, equal to, less than) the current at location B. b. The current at location B is _____ (greater than, equal to, less than) the current at location E. c. The current at location G is _____ (greater than, equal to, less than) the current at location F. d. The current at location E is _____ (greater than, equal to, less than) the current at location G. e. The current at location B is _____ (greater than, equal to, less than) the current at location F. f. The current at location A is _____ (greater than, equal to, less than) the current at location L. g. The current at location H is _____ (greater than, equal to, less than) the current at location I. Question 2. [15 Marks] Analyze the following circuit and determine the values of the total resistance, total current, and the current at and voltage drops across each individual resistor. 1 Part B: Semiconductors Question 3. [10 Marks] A semiconductor of composition 20%Na2O-80%SiO2 and a density of approximately 2.4g.cm3 has a conductivity of 8.25x10-6 (Ω-m)-1 at 150oC. If the conduction occurs by the diffusion of Na+ ions, what is their drift mobility (μ)? Data: Atomic masses of Na, O and Si are 23, 16 and 28.1 respectively. Question 4. [15 Marks] Suppose that the electrical conductivity of the semiconductor MgO is determined primarily by the diffusion of Mg2+ ions. Estimate the mobility of Mg2+ ions and calculate the electrical conductivity of MgO at 1800oC. Data: Diffusion Constant of Mg in MgO = 0.0239 cm2/s; lattice parameter of MgO, a=0.396x10-7cm; Activation Energy for the Diffusion of Mg2+ in MgO = 79,000cal/mol; k=1.987cal/K=k-mol; For MgO, Z=2/ion; q=1.6x10-19C; kB=1.38x10-23J/K-mol Hint: First calculate the diffusion coefficient D. Know that MgO has 4 Mg2+ and 4 O2- Per cell. 2