A network of resistances is formed as shown in Fig.14. Compute the resistance between the points A and B.
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Fig. 14(a)
The star connection by the resistors \(3\ \mathrm{\Omega}\),\(4\ \mathrm{\Omega}\) and\(6\ \mathrm{\Omega}\) is converted to delta connection, we have by the redraw of Fig. 14
\(R_1=\frac{6\times3+3\times4+4\times6}{3}=18\ \mathrm{\Omega}\)
\(R_2=\frac{6\times3+3\times4+4\times6}{4}=13.5\ \mathrm{\Omega}\)
\(R_3=\frac{6\times3+3\times4+4\times6}{6}=9\ \mathrm{\Omega}\)
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Fig. 14(b)
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Fig. 14(c)
\(R_4=\frac{9\times18}{9+18}=6\ \mathrm{\Omega}\)
\(R_4=\frac{1\times13.5}{1+13.5}=0.93\ \mathrm{\Omega}\)
\(R_4=\frac{9\times1}{9+1}=0.9\ \mathrm{\Omega}\)
Hence the resistance between terminals A and B is \(6\ \mathrm{\Omega}\)
What is meant by hysteresis in a magnetic circuit? What is the significance of B-H curve?
What is resonance? Deduce the expression of frequency in a series RLC circuit and parallel RLC circuit at resonance.
1.png)
Fig. 15(a)
Fig.23