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3 years ago

The voltage of electricity traveling away from a power plant is very high. How high may it be? Why is the voltage so high?

1 answer:

8 0

- The voltage travelling away from a power plant through transmission lines is very high, and it is typically of hundreds of kilovolts (typical values are between 138 kV and 765 kV).

- The main reason to use these high values of voltage is to reduce power dissipation.
In fact, the cables that are used to transmit electricity have a certain resistance R which is fixed. The power generated from the power plant and that should be transmitted through the lines is P, and it is also fixed.
The power dissipated through the cables is calculated as
$P_{diss}=I^2 R = (\frac{P}{V} )^2 R$
where I is the current and V the voltage.
As it can be seen, using higher voltages reduce the amount of power dissipated through the lines (while using higher currents will have the opposite effect).

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kvv77 [185]

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here we can see that gravitational potential energy inversely varies with the distance

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So gravitational potential energy is minimum at the nearest point and maximum at the farthest point

PART b)

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Part C)

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3 years ago

In a cyclic process, a gas performs 123 J of work on its surroundings per cycle. What amount of heat, if any, transfers into or

Margaret [11]

Answer:

123 J transfer into the gas

Explanation:

Here we know that 123 J work is done by the gas on its surrounding

So here gas is doing work against external forces

Now for cyclic process we know that

$\Delta U = 0$

so from 1st law of thermodynamics we have

$dQ = W + \Delta U$

$dQ = W$

so work done is same as the heat supplied to the system

So correct answer is

123 J transfer into the gas

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3 years ago

A truck accelerates From being stopped to 18 m/s in 5.5 seconds. A bus accelerates from being stopped to 24 m/s in 6.0 seconds.

Mars2501 [29]

Answer:

The bus

Explanation:

a = (v-u)/t

Where

a = acceleration

v = final velocity

u = initial velocity

t = time taken

For truck to get its acceleration,

a = (18-0)/5.5 = 3.27 ms⁻²

For bus to get its acceleration,

a = (24-0)/6 = 4 ms⁻²

As 4 > 3.27 bus has a greater acceleration.

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3 years ago

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Answer:

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Answer:

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3 years ago