Question

Why is power in transmission lines transmitted at high voltages
if power loss is directly proportional to V^{2}?

Answer #1

Voltage is the characteristic property of charge & it doesn't matter whether charge is in rest or in motion.

As we know that, resistance is only offered when charges are begins to move.

conductor having higher voltage simply lay there and will not do any work. hence no loss in energy.

when flow of current begins, offered resistance leads to power loss, i.e. power loss = i^2*R ........(1)

since we know,

Power, P = V*I ......(2)

in power transmission, voltage is much higher. hence from equation 2, current flow is very low. From equation 1, power loss is less.

thats the reason why power transmission takes place with higher voltage rather than with higher current.

{Note : Power loss is function of Current,I & resistance R, not Voltage,V & resistance R}

Explain why long-distance electric transmission lines operate at
high voltages.

32-2 Power transmission
Why do power transmission lines use high voltage? An
electric power station sends out a fixed 40 MW of power. The
cross-country power line wires from the power station to the city
has a total resistance of 7 Ω. Assume the circuit consists of the
power station, the line wire (resistor), the city (resistor), and a
storage battery.
Find the power loss (in kW) in the wires using a line
voltage of
a) 500 kV
b) 20...

Why is long distance power transmission sent on high
voltage (high tension) wires? Compare two identical
transmission lines delivering the same amount of power: the first
at twice the voltage of the second. Which of the two
lines is most advantageous to a utility
company? Numerically, how much is the
advantage?

Electric Power Systems
What is transposition , why the transmission lines are
transposed?
please explain it by all details with good and clear hand
writing

5. Overvoltage protection of power transmission lines.

List various types of faults occurring in power transmission
lines.

A high-voltage transmission line with a resistance of 0.28 Ω/km
carries a current of 1030 A. The line is at a potential of 670 kV
at the power station and carries the current to a city located 155
km from the station.
(a) What is the power loss due to resistance in the line?
MW
(b) What fraction of the transmitted power does this loss
represent?
%

Why
platinum resistance is directly proportional to temperature and
thermistor resistor is inversely proportional?

Why is electric power for domestic use in the United States,
Canada, and most of the Western
Hemisphere transmitted at very high voltages and stepped down to
120 V by a transformer
near the point of consumption?

11000 W of electric power can be transmitted to a distant
station at (a) 220 V or (b) 22000 V. Find the current in secondary
coil in both cases (a) and (b). Which of the two modes of power
transmission should be preferred and why? Assume resistance of
transmission line is ‘R’ used for power transmission. Support your
answer with possible calculations.

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