1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Llana [10]
3 years ago
11

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

this transformer is being replaced so that its output can be 500 kV for more efficient cross-country transmission on upgraded transmission lines.
(a) What is the ratio of turns in the new secondary compared with turns in the old secondary
(b) What is the ratio of new current output to old output (at 425 kV) for the same power?
(c) If the upgraded transmission lines have the same resistance, what is the ratio of new line power loss to old?
Physics
1 answer:
enot [183]3 years ago
7 0

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.

You might be interested in
A ringing bell sends sound waves in all<br> directions<br> places<br> sides
Strike441 [17]

Answer:

direction

Explanation:

because particles surround the bell, so when the bell vibrates, it causes particles surrounding it to vibrate back and forth vigorously. as these particles vibrate they collide with the neighbouring particles, passing on the energy.

hope this is what you are asking, if not please report it so that someone else gets to try it.

4 0
3 years ago
1. Applying _____ indicates that layers were repositioned from a flat-lying orientation.
saveliy_v [14]

Answer:

1. the principle of original horizontality

2. the principle of crosscutting relationships

3. the law of superposition

4. older

5. younger

5 0
3 years ago
Which one of the following is a decomposition reaction?
horsena [70]
It would be A because Decomposition is when a substance breaks down into two. 
8 0
3 years ago
Read 2 more answers
In the process of melting, what best describes what happens to a solid?
Eduardwww [97]
<span>a. A solid will gain kinetic energy and become a liquid.</span>
5 0
3 years ago
Read 2 more answers
A tree performing photosynthesis is an example of _____________
Fittoniya [83]

Answer:Chemical

Explanation:Photosynthesis is the biochemical reaction through which all green plants, including trees, make their food to live and grow.

3 0
3 years ago
Other questions:
  • Two infinite, uniformly charged, flat surfaces are mutually perpendicular. One of the sheets has a charge density of +60 pC/m2,
    9·2 answers
  • What is another name for the electromagnetic spectrum?
    5·1 answer
  • If the average speed of an orbiting space shuttle is 27 800 km/h, determine the time required for it to circle Earth. Assume tha
    13·1 answer
  • If a sphere with radius r is inscribed in a cube with edges of length e, which of the following expresses the relationship betwe
    6·1 answer
  • The football players collide head-on in midair while trying to catch a thrown football. The first player is 95.0 kg and has an i
    5·1 answer
  • In extremely large​ forests, it is not​ cost-effective to position forest rangers in towers or to use small aircraft to continua
    9·1 answer
  • According to Kepler's Third Law, a solar-system planet that has an orbital radius of 1 AU would have an orbital period of about
    11·1 answer
  • What is formed when two or more
    11·2 answers
  • Why is a protective apron or lab coat important to use when working with acids?
    15·2 answers
  • 2 t of ferrous scrap at a temperature of 20 degrees is heated to the melting point and melted. How much to consume?
    14·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!