How to tell that the magnetic field is going into the page

In summary, the conversation discusses a problem with a parallel plate capacitor and a uniform magnetic charge. There is a question about the direction of the magnetic field and the use of symbols to represent it. The conclusion is that the symbols are not arbitrary and are used to indicate the direction of the field.
  • #1
Perseverence
88
7
I attached the image of the problem . I'm sorry if it is unreadable. It essentially says that there is a parallel plate capacitor with a uniform electric charge in the space between the plates. And a uniform magnetic charge is in the space between the plates which is produced by another device. The velocity of a charge moves towards the right of the page. the given information in the attached problem, it's clear that the left hand rule is used with the thumb pointing to the right. But I don't see any information that would indicate why the magnetic field will be going into the page. It seems that the magnetic fields could be just as usually be going down the page or up the page.
 

Attachments

  • 20180121_014847.jpg
    20180121_014847.jpg
    21.2 KB · Views: 514
Physics news on Phys.org
  • #2
"x" denotes a field going into the paper, a circle with a dot in the center denotes a field coming out of the plane. You can imagine them as seeing the tail and head of an arrow, respectively. This is purely a convention.
 
  • #3
mfb said:
"x" denotes a field going into the paper, a circle with a dot in the center denotes a field coming out of the plane. You can imagine them as seeing the tail and head of an arrow, respectively. This is purely a convention.
I understand that those are the symbols for showing the direction of the field. But I'm trying to figure out how they derived that direction in the first place from the given information.
 
  • #4
Perseverence said:
I understand that those are the symbols for showing the direction of the field. But I'm trying to figure out how they derived that direction in the first place from the given information.
I understand the left and right-hand rules, but from the given problem there doesn't seem to be enough information to know which direction the magnetic field would be going. Somehow they infer that it is going into the page
 
  • #5
mfb said:
"x" denotes a field going into the paper, a circle with a dot in the center denotes a field coming out of the plane. You can imagine them as seeing the tail and head of an arrow, respectively. This is purely a convention.
Ohhhh duh! I understand what you were saying now! Goodness gracious! Those x''s are not arbitrary symbols on this problem. You are a lifesaver. I know it seemed really obvious to you and now it seems really obvious to me.

Thank you thank you thank you thank you thank you! Physics Forum rules!
 

1. How can I determine the direction of a magnetic field?

The direction of a magnetic field can be determined by using a compass or a magnetic needle. The north pole of a compass or needle will point towards the direction of the magnetic field lines.

2. What is the right-hand rule for determining the direction of a magnetic field?

The right-hand rule states that if you point your thumb in the direction of the current flow, your fingers will curl in the direction of the magnetic field lines. If the magnetic field is going into the page, your fingers will curl in a clockwise direction.

3. How can I tell if the magnetic field is going into the page or out of the page?

To determine if the magnetic field is going into the page or out of the page, you can use the right-hand rule. Point your thumb in the direction of the current flow and observe the direction in which your fingers curl. If they curl in a clockwise direction, the magnetic field is going into the page. If they curl in a counterclockwise direction, the magnetic field is going out of the page.

4. Can I use a bar magnet to determine the direction of a magnetic field?

Yes, a bar magnet can also be used to determine the direction of a magnetic field. Place the bar magnet near the area where the magnetic field is present and observe the direction in which the north pole of the magnet is pointing. This will be the direction of the magnetic field lines.

5. Are there any other methods for determining the direction of a magnetic field?

Yes, there are other methods for determining the direction of a magnetic field. One method is using a magnetic field indicator, which is a small compass-like device that can directly show the direction of a magnetic field. Another method is using a magnetic field sensor, which can measure the strength and direction of a magnetic field and display it on a digital screen.

Similar threads

  • Introductory Physics Homework Help
Replies
16
Views
338
  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
262
  • Introductory Physics Homework Help
2
Replies
43
Views
2K
  • Introductory Physics Homework Help
Replies
9
Views
966
  • Introductory Physics Homework Help
Replies
31
Views
970
  • Introductory Physics Homework Help
Replies
7
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
931
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
4
Views
269
Back
Top