Question

If the direct transmission method with a cable of resistance $0.4\Omega k{m}^{-1}$ is used, the power dissipation (in %) during transmission is

• A. 20
• B. 30
• C. 40
• D. 50

Answer 1

The correct option is B 30

$R=0.4\times 20=8\Omega$

Power loss$=\frac{loss}{input}\times 100$

$=\frac{\frac{{\upsilon }^2}{R}}{600K}\times 100=\frac{4000\times 4000}{600\times 1000\times 8}\times 100=33.33\approx 30$