Current Electricity - Result Question 64

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69. Two cities are $150 km$ apart. Electric power is sent from one city to another city through copper wires. The fall of potential per $km$ is 8 volt and the average resistance per $km$ is $0.5 \Omega$. The power loss in the wires is :

======= ####69. Two cities are $150 km$ apart. Electric power is sent from one city to another city through copper wires. The fall of potential per $km$ is 8 volt and the average resistance per $km$ is $0.5 \Omega$. The power loss in the wires is :

3e0f7ab6f6a50373c3f2dbda6ca2533482a77bed:content/english/neet-pyq-chapterwise/physics/current-electricity/current-electricity—result-question-64.md (a) $19.2 W$

(b) $19.2 kW$

(c) $19.2 J$

(d) $12.2 kW$

[2014]

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Answer:

Correct Answer: 69. (b)

Solution:

  1. (b) Total resistance $R=(0.5 \Omega / km) \times(150 km)$ $=75 \Omega$

Total voltage drop $=(8 V / km) \times(150 km)=1200 V$

Power loss $=\frac{(\Delta V)^{2}}{R}=\frac{(1200)^{2}}{75} W$

$=19200 W=19.2 kW$