# Electromagnetic waves Conceptual help please

• MEAHH
In summary, the conversation discusses the effects of an electromagnetic plane wave on a steel wire connected to a light bulb. In the first scenario, where the wire is parallel to the y-axis and the bulb is centered on the x-axis, the bulb will glow due to the wire's interaction with the E field vector. In the second scenario, where the wire is tilted at different angles, the brightness of the bulb will vary depending on the wire's orientation and its interaction with the changing magnetic field.
MEAHH
Electromagnetic waves!Conceptual help please!

A long steel wire is cut in half is connected to a different terminal of a light bulb. An electromagnetic(EM) plane wave (E(x,y,z,t)=Esin(kx-wt)[y hat direction], B(x,y,z,t)=Bsin(kx-wt)[z hat direction]) moves past the wire.

a) Suppose the wire were oriented parallel to the y-axis, with the bulb centered on the x-axis. Would the bulb glow?
I said yes because the wire is parallel to the E field vector, causing the electrons in the wire to oscillate up and down crateing a current...Is my thinking corect or does the magnetic (B) vector affect it some how?

B)Suppose nstead that the wire were positioned as described below. Would the brightness of the bulb be greater than, less than, or equal to the brightness that it had in part a. Explain your reasoning.

i) The wire is parallel to the y-axis but its bottom end is located on the x-axis.
I think that it will be equal to the brightness in case a because the E field is the same on a line, meaning they have the same magnitude no matter the distance from the graph.

ii)the wire is tilted so that it makes an angle of 40 degrees with respect to the y-axis but is still parallel to the y-z plane.

In the wire current is induced only by changing magnetic field, not by changing electric field. And the current is maximum when the wire is perpendicular to the field.

. It may be slightly less bright because the wire is not parallel to the E field vector, causing some interference or diffraction effects. However, the B field may also play a role in inducing a current in the wire, so it could potentially be equal to or even slightly brighter than in part a. It would ultimately depend on the specific properties of the EM wave and the wire.

## 1. What are electromagnetic waves?

Electromagnetic waves are a type of energy that can travel through space. They are created when an electric charge vibrates or accelerates, and they consist of both electric and magnetic fields that oscillate at right angles to each other.

## 2. What is the electromagnetic spectrum?

The electromagnetic spectrum is the range of all possible frequencies of electromagnetic radiation. This includes radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, and gamma rays. Each type of electromagnetic wave has a different frequency, wavelength, and energy.

## 3. How do electromagnetic waves differ from other types of waves?

Electromagnetic waves are unique because they do not require a medium to travel through. This means they can travel through a vacuum, such as outer space, unlike other types of waves which require a medium, such as water or air. Electromagnetic waves also have a constant speed, which is the speed of light.

## 4. What is the relationship between frequency and wavelength in electromagnetic waves?

The frequency of an electromagnetic wave is directly proportional to its wavelength. This means that as the frequency increases, the wavelength decreases, and vice versa. This relationship is described by the equation c = λf, where c is the speed of light, λ is the wavelength, and f is the frequency.

## 5. How are electromagnetic waves used in everyday life?

Electromagnetic waves have a wide range of applications in our daily lives. Radio waves are used for communication, microwaves for cooking, infrared for thermal imaging, visible light for vision, ultraviolet for sterilization, X-rays for medical imaging, and gamma rays for cancer treatment. They are also used in technologies such as Wi-Fi, cell phones, and satellite communication.

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