UrbanPro

Take Class 10 Tuition from the Best Tutors

  • Affordable fees
  • 1-1 or Group class
  • Flexible Timings
  • Verified Tutors

Search in

why does high tension wires produce humming sound ?

Asked by Last Modified  

Follow 0
Answer

Please enter your answer

The audible noise emitted from high-voltage lines is caused by the discharge of energy that occurs when the electrical field strength on the conductor surface is greater than the 'breakdown strength' (the field intensity necessary to start a flow of electric current) of the air surrounding the conductor....
read more
The audible noise emitted from high-voltage lines is caused by the discharge of energy that occurs when the electrical field strength on the conductor surface is greater than the 'breakdown strength' (the field intensity necessary to start a flow of electric current) of the air surrounding the conductor. This discharge is also responsible for radio noise, a visible glow of light near the conductor, an energy loss known as corona loss and other phenomena associated with high-voltage lines. "The degree or intensity of the corona discharge and the resulting audible noise are affected by the condition of the air--that is, by humidity, air density, wind and water in the form of rain, drizzle and fog. Water increases the conductivity of the air and so increases the intensity of the discharge. Also, irregularities on the conductor surface, such as nicks or sharp points and airborne contaminants, can increase the corona activity. Aging or weathering of the conductor surface generally reduces the significance of these factors. "The higher voltages at which modern transmission lines operate have increased the noise problem to the point to which they have become a concern to the power industry. Consequently, these lines are now designed, constructed and maintained so that during dry conditions they will operate below the corona-inception voltage, meaning that the line will generate a minimum of corona-related noise. In foul weather conditions, however, corona discharges can be produced by water droplets, fog and snow." read less
Comments

Two reasons: One is coronal discharge. The high voltage between adjacent wires (phases) is enough to make air conduct. As the voltage between phases is alternating, and constantly changing, the sound changes. Second reason: Current through the wire isn't fixed. The varying current causes expansion...
read more
Two reasons: One is coronal discharge. The high voltage between adjacent wires (phases) is enough to make air conduct. As the voltage between phases is alternating, and constantly changing, the sound changes. Second reason: Current through the wire isn't fixed. The varying current causes expansion and contraction of the wire, producing sound. Especially of concern is power factor far from 1, with current much higher at the peaks. Most electrical transmission is done three phase. So at 120 Hz and 120 degrees apart, each wire will expand slightly, creating a click, and the effective frequency might be as high as 480 Hz, explaining why it might sound higher in pitch. read less
Comments

Perl Developer | Perl Trainer

The reason for this is something known as "magnetostriction", which is strain induced in a magnetic lattice due to the magnetic nature of a material. There is a pretty good explanation of the buzzing noises in transformers here, but the summary is that the ferromagnetic domains in the transformer core...
read more
The reason for this is something known as "magnetostriction", which is strain induced in a magnetic lattice due to the magnetic nature of a material. There is a pretty good explanation of the buzzing noises in transformers here, but the summary is that the ferromagnetic domains in the transformer core are subjected to the 60Hz (in the US) oscillations of the magnetic field due to the AC current. Because of the electrical cycle, there are two impacts on the core per AC oscillation, so the strain is changing at 60 Hz, which produces the 120 Hz noise that we can identify a "great B" note. read less
Comments

"The audible noise emitted from high-voltage lines is caused by the discharge of energy that occurs when the electrical field strength on the conductor surface is greater than the 'breakdown strength' (the field intensity necessary to start a flow of electric current) of the air surrounding the conductor....
read more
"The audible noise emitted from high-voltage lines is caused by the discharge of energy that occurs when the electrical field strength on the conductor surface is greater than the 'breakdown strength' (the field intensity necessary to start a flow of electric current) of the air surrounding the conductor. This discharge is also responsible for radio noise, a visible glow of light near the conductor, an energy loss known as corona loss and other phenomena associated with high-voltage lines. read less
Comments

View 2 more Answers

Related Questions

What is the Critical angle of diamond?
The speed of light in vacuum to the speed of light in the medium: Index of refraction : n = c / v .
T V
Covalency means?
The number of covalent bonds that a particular atom can make with other atoms in forming a molecule.
Ravi Ranjan
0 0
7
How is sound produced in Thunder?
Thunder is the sound caused by lightning. Depending on the distance and nature of the lightning, thunder can range from a sharp, loud crack to a long, low rumble (brontide). The sudden increase in pressure...
Guru
0 0
5
What is fission?
Fission is another word for splitting. The process of splitting a nucleus is called nuclear fission. Uranium or plutonium isotopes are normally used as the fuel in nuclear reactors, because their atoms...
Ravi Ranjan
1 0
8
What is forestry? Explain.
The natural growth of vegetation, including flora as well as fauna in any geographical territory, is known as a forest. While the human interference grown vegetation is termed as forestry. Some of the...
Kishore

Now ask question in any of the 1000+ Categories, and get Answers from Tutors and Trainers on UrbanPro.com

Ask a Question

Related Lessons

Difference between Prime and Composite Numbers
A prime number is a whole number that only has two factors which are itself and one. A composite number has factors in addition to one and itself. The numbers 0 and 1 are neither prime nor composite. All...

5-Study Tips every student needs to follow to get results
Tip-1 of Study Tips:Trying to do all tasks together First and foremost thing to do for being more productive is to prioritize our tasks. When you're clear about your priorities, you never try to do all...

* Solving Science numericals or math question
While solving Science numericals or math question always follow below steps. * Write all the parameteres given in question with unit * Think what to be find or calculated * Think how to proceed * Write...

EVS: Waste Management
Report: A Preliminary Study And Possible Solutions For Municipal Solid Waste (MSW) Management Objective : MSW is a challenge to urbanization. It causes air pollution, land contamination, hygiene issues,...

Trigonometric Formula
We will learn how to remember the trigonometric Formula in different quadrants. 1. Quadrant 1-(0° to 90°) - All functions are positive 2. Quadrant 2-(90° to 180°) - Sine & Cosec...

Akhilesh Choudhary

1 0
0

Recommended Articles

Sandhya is a proactive educationalist. She conducts classes for CBSE, PUC, ICSE, I.B. and IGCSE. Having a 6-year experience in teaching, she connects with her students and provides tutoring as per their understanding. She mentors her students personally and strives them to achieve their goals with ease. Being an enthusiastic...

Read full article >

Quest Academy is a professional Bangalore based NEET and JEE (Main + Advanced) training institute. The academy was incorporated in 2015 to cater to the needs of students, who aim to crack competitive exams by connecting with the best brains around. The institute helps students enhance their skills and capabilities through...

Read full article >

Mohammad Wazid is a certified professional tutor for class 11 students. He has 6 years of teaching experience which he couples with an energetic attitude and a vision of making any subject easy for the students. Over the years he has developed skills with a capability of understanding the requirements of the students. This...

Read full article >

Swati is a renowned Hindi tutor with 7 years of experience in teaching. She conducts classes for various students ranging from class 6- class 12 and also BA students. Having pursued her education at Madras University where she did her Masters in Hindi, Swati knows her way around students. She believes that each student...

Read full article >

Looking for Class 10 Tuition ?

Learn from the Best Tutors on UrbanPro

Are you a Tutor or Training Institute?

Join UrbanPro Today to find students near you
X

Looking for Class 10 Tuition Classes?

The best tutors for Class 10 Tuition Classes are on UrbanPro

  • Select the best Tutor
  • Book & Attend a Free Demo
  • Pay and start Learning

Take Class 10 Tuition with the Best Tutors

The best Tutors for Class 10 Tuition Classes are on UrbanPro

This website uses cookies

We use cookies to improve user experience. Choose what cookies you allow us to use. You can read more about our Cookie Policy in our Privacy Policy

Accept All
Decline All

UrbanPro.com is India's largest network of most trusted tutors and institutes. Over 55 lakh students rely on UrbanPro.com, to fulfill their learning requirements across 1,000+ categories. Using UrbanPro.com, parents, and students can compare multiple Tutors and Institutes and choose the one that best suits their requirements. More than 7.5 lakh verified Tutors and Institutes are helping millions of students every day and growing their tutoring business on UrbanPro.com. Whether you are looking for a tutor to learn mathematics, a German language trainer to brush up your German language skills or an institute to upgrade your IT skills, we have got the best selection of Tutors and Training Institutes for you. Read more