WBJEE · Physics · Current Electricity
An electrical cable having a resistance of \(0.2 \Omega\) delivers \(10 \mathrm{kw}\) at \(200 \mathrm{~V}\) D.C. to a factory. What is the efficiency of transmission?
- A \(65 \%\)
- B \(75 \%\)
- C \(85 \%\)
- D \(95 \%\)
Answer & Solution
Correct Answer
(D) \(95 \%\)
Step-by-step Solution
Detailed explanation
\(P=V I \Rightarrow I=\frac{10 \times 10^3}{200}=50 A\), Power loss \(=(50)^2(0.2)=500 \mathrm{~W}\) Efficiency \(=\frac{10000 \times 100}{10000+500}=95.23 \%\)
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