A) \[89.5%\]
B) \[99.5%\]
C) \[79.5%\]
D) \[90.5%\]
Correct Answer: B
Solution :
Let \[x\] watt be the power loss in transmission line in the form of heat \[\therefore \] \[x={{\left( \frac{P}{V} \right)}^{2}}=R{{\left( \frac{20\times 1000}{400} \right)}^{2}}\times 0.4\] \[={{\left( \frac{200}{4} \right)}^{2}}\times 0.4=50\times 50\times 0.4\] Efficiency of transmission\[=\frac{\text{Power}\,\,\text{delivered}}{\text{Power}\,\,\text{supplied}}\] \[=\frac{20\,\,kW}{20\,\,kW+0.1\,\,kW}=\frac{20\,\,kW}{20.1\,\,kW}\] \[=\frac{20}{20.1}\approx 99.5%\]You need to login to perform this action.
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