Direction of magnetic field in antenna

In summary, the conversation discusses the direction of magnetic field lines and the flow of current in an electrical circuit. It is concluded that the current flows in a clockwise direction and does not flow through empty space. The flow of charge and current is described in detail, with the understanding that it will eventually reach a point of equilibrium. The conversation ends with a compliment on the explanation.
  • #1
sparkle123
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60513b78.png

In the middle picture, since the current is directed downward (I think), by the right hand rule shouldn't the magnetic field lines be clockwise?
Thanks!
 
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  • #2
'Positives' (conventional charge) looks like it is flowing up into the top element, and up out of the bottom element ('leaving behind' a -ve charge), just like the arrows show. No?
 
  • #3
Thanks!
but the purple arrows I(t) are flowing down?
Also, I'm not sure if the current can flow down the conductors through empty space...
 
  • #4
Hi sparkle123! :smile:

No the current does not flow through empty space.
The purple arrow from the plus pole continues its flow into the upper rod where it dead-ends, resulting in a increasingly positive charge.
In the upper rod the current flows up.

Similarly, charge from the lower rod is sucked into the battery, resulting in a current flowing up in the lower rod.

These flows cannot continue indefinitely, since the charge has nowhere else to go.
So soon after the current starts flowing, the current diminishes until it is zero.
 
  • #5
Thanks I like Serena! :) That makes so much more sense!
I wish the textbook explained it the way you did - it just says that when the rods are fully charged, the current is zero.
 
  • #6
Thanks! :blushing:
 

1. What is the direction of the magnetic field in an antenna?

The direction of the magnetic field in an antenna is perpendicular to the direction of the electric field and also perpendicular to the direction of propagation of the electromagnetic wave.

2. How does the direction of the magnetic field affect the performance of an antenna?

The direction of the magnetic field has a direct impact on the polarization of the electromagnetic wave, which in turn affects the gain and efficiency of the antenna. A mismatch in the direction of the magnetic field can result in decreased performance of the antenna.

3. Can the direction of the magnetic field be changed in an antenna?

The direction of the magnetic field in an antenna is determined by the geometry and design of the antenna. It is not easily changeable, but can be altered by adjusting the orientation or position of the antenna.

4. Is the direction of the magnetic field the same for all types of antennas?

No, the direction of the magnetic field can vary depending on the type of antenna. For example, a dipole antenna has a magnetic field that is perpendicular to the axis of the antenna, while a loop antenna has a magnetic field that is parallel to the axis of the antenna.

5. How does the direction of the magnetic field relate to the radiation pattern of an antenna?

The direction of the magnetic field plays a crucial role in determining the shape and orientation of the radiation pattern of an antenna. It is directly connected to the directionality and polarization of the electromagnetic wave emitted by the antenna.

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