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2 years ago

As an electromagnetic wave travels, what is the relationship between the

Physics

2 answers:

galina1969 [7]2 years ago

7 0

The answer is a tell me if I am wrong.

ahrayia [7]2 years ago

5 0

Answer:

Its D

Explanation:

They are at a 90° angle to each other.

Do good on your tests :]

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A large power plant generates electricity at 12.0 kV. Its old transformer once converted the voltage to 385 kV. The secondary of

enot [183]

Answer:

a) In the new transformer there are 42 turns in the secondary per turn in the primary, while in the old transformer there were 32 turns per turn in the primary.

b) The new output is 86% of the old output

c) The losses in the new line are 74% the losses in the old line.

Explanation:

a) To relate the turns of primary and secondary to the ratio of voltage we have this expression:

$\frac{n_1}{n_2}=\frac{V_1}{V_2}$

In the old transformer the ratio of voltages was:

$\frac{n_1}{n_2}=\frac{V_1}{V_2}=\frac{12}{385} =0.03117\\\\n_2=n_1/0.03117=32.1n_1$

In the new transformer the ratio of voltages is:

$\frac{n_1}{n_2}=\frac{V_1}{V_2}=\frac{12}{500} =0.024\\\\n_2=n_1/0.24=41.7n_1$

In the new transformer there are 42 turns in the secondary per turn in the primary, while in the old transformer there were 32 turns per turn in the primary.

b) The new current ratio is

$\frac{V_1}{V_2}=\frac{I_2}{I_1}=\frac{12}{500}= 0.024\\\\I_2=0.024I_1$

If the old current output was 425 kV, the ratio of current was:

$\frac{V_1}{V_2}=\frac{I_2}{I_1}=\frac{12}{425}= 0.028\\\\I_2=0.028I_1$

Then, the ratio of the new output over the old output is:

$\frac{I_{2new}}{I_{2old}} =\frac{0.024\cdot I_1}{0.028\cdot I_1}= 0.86$

The new output is 86% of the old output (smaller output currents lower the losses on the transmission line).

c) The power loss is expressed as:

$P_L=I^2\cdot R$

Then, the ratio of losses is (R is constant for both power losses):

$\frac{P_n}{P_o} =\frac{I_n^2R}{I_o^2R} =(\frac{I_n}{I_o} )^2=0.86^2=0.74$

The losses in the new line are 74% the losses in the old line.

7 0

2 years ago

Which of the following is NOT a property of long-period comets that suggests that they originate from the Oort cloud?

Lesechka [4]

Answer:

b. They orbit around the Sun in a counterclockwise direction, when viewed from above the ecliptic plane.

Explanation:

All the objects of the solar system revolve around the Sun in a counterclockwise direction. The comet coming from the Oort's cloud will also follow the same kind of orbit. That is why it can't be a property to distinguish an Oort's cloud comet.

All other properties are correct to identify an Oort's cloud comet as the Oort's cloud is a considered a spherical cloud just outside the Solar system.

7 0

2 years ago

What hidden costs of using DDT did Rachel Carson call attention to?

Sveta_85 [38]

Answer:

The ban was intended to prevent the imminent extinction of ospreys, peregrine falcons, and bald eagles, our national bird, among other species; they were vulnerable because DDT caused a fatal thinning of eggshells, which collapsed under the weight of the parent incubating them.

Explanation:

The hidden cost was to control pests was washing off into rivers and streams, poisoning fish, birds, and even humans with toxic chemicals.

Hope this helps

6 0

2 years ago

Select the correct answer.

Rina8888 [55]

Answer:

Explanation:

7 0

3 years ago

High rate of evaporation in a water cycle can most likely cause

scoray [572]

Answer: d. thunderstorms
The option <span>blizzards can be excluded as it is clearly not related to the evaporation. Floods can happen if the condensation rate high, not evaporation. Sometimes the cloud that carries water is just blown up by the wind so the evaporation does not happen in that place.
Thunderstorms happen more in summer because the rate of evaporation and condensation is increased.</span>

3 0

3 years ago

Read 2 more answers