• Support PF! Buy your school textbooks, materials and every day products Here!

Magnitude and Direction of Magnetic Field

  • #1

Homework Statement


An electron experiences the greatest force as it travels 2.9 x 10^6 ms in a magnetic field when it is moving northward. The force is upward and of magnitude 7.2 x 10^-13 N. What are the magnitude and direction of the magnetic field?


Homework Equations





The Attempt at a Solution


I don't even know how to get a diagram going for this. Anything would be helpful. Thank you.
 

Answers and Replies

  • #2
rock.freak667
Homework Helper
6,230
31
What is the force exerted by a magnetic field of strength B, on a charge Q, moving at a velocity v?

F=?

When you get that it becomes simple algebra.

If the electron is moving northwards, what direction should the field be pointing?
 
  • #3
I'm using F(max) = qvB because it seems that it's 90 degrees. The field should be 90 degrees relative to the upward force, so the field is perpendicular, or horizontal, right?

Also, because of the charge on the electron, i get a negative answer (in Tesla). does this mean that i indicate the negative charge as "eastward?"

please see attached. thank you!
 

Attachments

  • #4
rock.freak667
Homework Helper
6,230
31
I'm using F(max) = qvB because it seems that it's 90 degrees. The field should be 90 degrees relative to the upward force, so the field is perpendicular, or horizontal, right?

Also, because of the charge on the electron, i get a negative answer (in Tesla). does this mean that i indicate the negative charge as "eastward?"

please see attached. thank you!
I think if it is negative then your field should be pointing in the opposite direction that you took as the +ve direction.
 

Related Threads for: Magnitude and Direction of Magnetic Field

Replies
3
Views
2K
Replies
6
Views
5K
Replies
0
Views
11K
Replies
4
Views
565
Replies
1
Views
3K
Replies
3
Views
4K
Replies
5
Views
351
Replies
2
Views
7K
Top