# 2 questions in Electric and magnetic fields in space.

• convict11
Wavelength = c/f = 3 x 10e8 / 8.5 x 10e7 = 3.5 metersAntenna length = wavelength/4 = 3.5/4 = 0.875 metersIn summary, the first question asks for the energy given up by an electron passing between the cathode and anode of a spark plug with a potential difference of 1.0x10^4V. The second question asks for the wavelength and antenna length required to detect a television channel broadcasting at 85MHz. To find the wavelength, we use the equation speed of wave = frequency * wavelength, and to find the antenna length, we divide the wavelength by 4.

#### convict11

Hey all I was just wondering if anyone knows how to figure out these two questions.

1) The difference in potential between the cathode and the anode of a spark plug is 1.0x10^4V. What energy does an electron give up as it passes between the electrodes?

This one I am really pretty clueless.

2) Television channel 6 broadcasts on a frequency of 85MHz. What is the wavelength of the electromagnetic wave broadcast on channel 6? What is the length of an antenna that will detect channel 6 most easily?

I read somewhere that to figure out radio wave length you take the megahertz and divide it into 300. Which works out to 3.5. I am not sure if this is the correct way to do it seems sort of simple.

If anyone could give any help would be appreciated also any sites where I can better learn the material being used would be great. Thanks.

1) Use the relationship between voltage and energy, its really simple.

2) Speed of wave = Frequency * Wavelength

Speed of wave = c = 3 x 10e8
Frequency = 85MHz = 8.5 x 10e7 Hz

1) To figure out the energy an electron gives up as it passes between the electrodes, you can use the formula: E = qΔV, where E is the energy, q is the charge of the electron (1.6x10^-19 coulombs), and ΔV is the potential difference (1.0x10^4V). So, the energy would be 1.6x10^-19 x 1.0x10^4 = 1.6x10^-15 Joules.

2) You are correct in your calculation for finding the wavelength of the electromagnetic wave. The formula is λ = c/f, where λ is the wavelength, c is the speed of light (3x10^8 m/s), and f is the frequency (85 MHz). So, the wavelength would be 3x10^8 / 85x10^6 = 3.5 meters.

The length of an antenna that will detect channel 6 most easily would ideally be half of the wavelength, so in this case, it would be 1.75 meters. However, the actual length of the antenna can vary depending on factors such as the type of antenna and the surrounding environment.

Some helpful resources to learn more about electric and magnetic fields in space include NASA's website, which has a section dedicated to space physics, and Khan Academy, which offers free online courses on various topics, including electromagnetism.

## 1. What are electric and magnetic fields in space?

Electric and magnetic fields are forms of energy that exist in space and are created by the movement of electrically charged particles. These fields interact with each other and with other objects in space, such as planets and stars.

## 2. How are electric and magnetic fields measured in space?

Electric and magnetic fields can be measured using specialized instruments on spacecrafts, such as magnetometers and electric field sensors. These instruments can detect the strength and direction of the fields, providing valuable data for scientists to study.

## 3. What is the difference between electric and magnetic fields?

The main difference between electric and magnetic fields is their direction of force. Electric fields exert a force on charged particles in the direction of the field, while magnetic fields exert a force perpendicular to the direction of the field.

## 4. How do electric and magnetic fields affect spacecrafts?

Electric and magnetic fields can have a significant impact on spacecrafts, as they can interfere with communication systems and affect the trajectory of the spacecraft. Scientists must carefully consider these fields when designing and operating spacecrafts in space.

## 5. What are some practical applications of studying electric and magnetic fields in space?

Studying electric and magnetic fields in space can provide valuable insights into the behavior of the universe and how it affects our planet. This knowledge can also be applied in various technologies, such as satellite communication and navigation systems, as well as in developing more efficient forms of energy production and transportation.

• Introductory Physics Homework Help
Replies
3
Views
829
• Introductory Physics Homework Help
Replies
5
Views
678
• Introductory Physics Homework Help
Replies
40
Views
646
• Introductory Physics Homework Help
Replies
5
Views
2K
• Introductory Physics Homework Help
Replies
9
Views
2K
• Electromagnetism
Replies
9
Views
1K
• Electromagnetism
Replies
41
Views
3K
• Introductory Physics Homework Help
Replies
4
Views
1K
• Introductory Physics Homework Help
Replies
3
Views
1K
• Introductory Physics Homework Help
Replies
33
Views
11K