Would the light bulb light up from the electromagnetic wave?

In summary: The answer to #2 would depend on whether the problem stated that the EM radiation was a plane wave, or...1. If the problem stated that the EM radiation was a plane wave, then the bulb would light up just as easily as it does with the parallel orientation of the electric and magnetic fields.2. If the problem stated that the EM radiation was a wave, then the orientation of the current carrying wire would not change the brightness of the bulb.
  • #1
nake9534
1
0
In the picture below

http://www.geo.mtu.edu/rs/back/spectrum/e_mag.gif

a bulb is placed on a wire parallel to the direction of the electric field. The bulb is directly on the x-axis where the two waves cross each other.

1. Would the bulb glow when the wire is parallel to the direction of the electric field?

The wire containing the bulb is now shifted up a distance on the plane of the electric field

2. Would the brightness of the bulb be greater than, less than, or equal to that of the brightness in 1?

Now imagine that the wire with the bulb is rotated 45 degrees so that it is now oriented between the electric and magnetic fields

3. Would the brightness of the bulb be greater than, less than, or equal to that of the brightness in 1?

// My Responses
//------------------------------------…
1. I think that the bulb would light up because the wire is parallel to that of the electric field and perpendicular to that of the magnetic field.

2. I think that the bulb would have the same brightness as in the first question because the orientation of the current carrying wire does not change.

3. I think that the bulb would be less bright than that in case 1 because neither field is in the optimum location to light the bulb.

A good explanation is much appreciated
Thanks
 
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  • #2
Edit: Bad info below! Leaving here to keep the thread together.

Couple of things here.

1. The diagram of the magnetic and electric fields of a photon are simply a visualization of how the fields work, a graph of the interaction of the fields. There is no "plane", the effect is in every direction. Both the magnetic and electric fields alternate from + to - and back over time in accordance with the frequency of the light.

2. A wire is MUCH MUCH MUCH bigger than a photon is. Even if there was a plane you could not align the wire.
 
Last edited:
  • #3
An electric current is induced onto a conductor of comparable length to the wavelength of the propagating wave.

An electrical load would experience this current if it were connected, for example, across the gap between two such aligned conductors, or between a conductor and a 'ground'.

The field would have to be very high to induce enough current to light a light bulb, but there would be a current. This is how radio signals are received by an antenna. It's why your TV or radio antenna has to be vertical or horizontal if the transmitter is also vertical or horizontal.
 
  • #4
Drakkith said:
Couple of things here.

1. The diagram of the magnetic and electric fields of a photon are simply a visualization of how the fields work, a graph of the interaction of the fields. There is no "plane", the effect is in every direction. Both the magnetic and electric fields alternate from + to - and back over time in accordance with the frequency of the light.

2. A wire is MUCH MUCH MUCH bigger than a photon is. Even if there was a plane you could not align the wire.

What do you think 'polarisation' is, if there is no 'plane'? How do antennas work?
 
  • #5
cmb said:
What do you think 'polarisation' is, if there is no 'plane'? How do antennas work?

Yeah, I guess you are right. I was thinking that the polarization had to do with something else, not the EM fields.
In retrospect I now remember several threads on photon polarization I've been in before. Guess I had a brain fart.
 
  • #6
nake9534 said:
In the picture below

http://www.geo.mtu.edu/rs/back/spectrum/e_mag.gif

a bulb is placed on a wire parallel to the direction of the electric field. The bulb is directly on the x-axis where the two waves cross each other.

1. Would the bulb glow when the wire is parallel to the direction of the electric field?

The wire containing the bulb is now shifted up a distance on the plane of the electric field

2. Would the brightness of the bulb be greater than, less than, or equal to that of the brightness in 1?

Now imagine that the wire with the bulb is rotated 45 degrees so that it is now oriented between the electric and magnetic fields

3. Would the brightness of the bulb be greater than, less than, or equal to that of the brightness in 1?

// My Responses
//------------------------------------…
1. I think that the bulb would light up because the wire is parallel to that of the electric field and perpendicular to that of the magnetic field.

2. I think that the bulb would have the same brightness as in the first question because the orientation of the current carrying wire does not change.

3. I think that the bulb would be less bright than that in case 1 because neither field is in the optimum location to light the bulb.

A good explanation is much appreciated
Thanks

In addition to cmb's comments...

The answer to #2 would depend on whether the problem stated that the EM radiation was a plane wave, or if its amplitude falls off away from the axis of travel. Does the problem statement of this schoolwork question say anything about that?
 

1. Can an electromagnetic wave make a light bulb light up?

Yes, an electromagnetic wave can make a light bulb light up if the wave has a high enough frequency and energy to generate photons. This is the principle behind how light bulbs work - they convert electrical energy into light energy.

2. What type of light bulb would work best with an electromagnetic wave?

Any type of light bulb that can convert electrical energy into light energy would work with an electromagnetic wave. This includes incandescent, fluorescent, and LED light bulbs.

3. What is the minimum frequency of an electromagnetic wave needed to light up a bulb?

The minimum frequency needed to light up a bulb depends on the type of bulb and its energy efficiency. Generally, a frequency in the visible light range (400-700 nanometers) is required to produce enough energy to light up a bulb.

4. Can any electromagnetic wave make a light bulb light up?

No, not all electromagnetic waves have enough energy to generate photons and light up a bulb. For example, radio waves and microwaves have lower frequencies and energies and would not be able to light up a bulb.

5. How does the electromagnetic wave interact with the atoms in the light bulb to make it light up?

When an electromagnetic wave reaches the light bulb, it transfers its energy to the atoms within the bulb. This causes the atoms to vibrate and release photons, which we perceive as light. This process is known as the photoelectric effect.

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