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Question 1 20 marks A businessman invested R250,000 at the beginning of a trading cycle, and made a profit of R100,000 after the first year. He desires to increase his profit by 20% the following year. Assuming that he is re-investing the whole of his original capital and a half of his profit, use feedback principles to determine: 1.1 gross output at the end of the first year; 1.2 forward gain for the first year in the absence of feedback; 1.3 gross output after the second year; 1.4 feedback ratio for the businessman; 1.5 system gain as a result of feedback 1.6 gross output and profit for the third year (state your assumptions, if any). [2] [2] [3] [3] [4] [6] 2.1 Question 2 20 marks Describe the concept of harmonics and harmonic distortion. Illustrate your answer with suitable annotated diagram(s). [10] 2.2 Show that harmonic distortion with negative feedback (NFB) is given by: D D D = 1+ BA where D is harmonic distortion without feedback. [5] 2.3 Similarly, show that noise distortion with NFB is given by: N N N = 1 + BA where N is noise without feedback. [5] Question 3 60 marks Write on ANY TWO practical applications of feedback concepts to real-life problems. The practical applications can be in any area, e.g. electronics, control systems, mechanical systems, automobile systems, banking and finance, business, economics, biological systems, medical sciences, industry, etc. Your answer should include a statement of the problem and how feedback concepts are used for solving it. The answer should be supported with [60] Page 1 of 2 relevant annotated diagrams, and any useful basic equations. Elaborate equations are not required. Between 4-6 pages are adequate.