My Math Forum How does the magnetic field varies here?

 Physics Physics Forum

 February 17th, 2019, 06:18 AM #1 Newbie   Joined: Feb 2019 From: United states Posts: 9 Thanks: 0 How does the magnetic field varies here? >A uniform beam of positively charged particles is moving with a constant velocity parallel to another beam of negatively charged particles moving with the same velocity but in opposite direction separated by a distance d. Then, how should be the variation of magnetic field B along a perpendicular line drawn between the two beams?(For better view, imagine positive beam to be x-axis and negative beam to be y=1 line.) I know that there will be electric field and hence the magnetic field. But I don't know how to proceed for the relation Last edited by Jayant98; February 17th, 2019 at 06:21 AM.
February 17th, 2019, 07:36 AM   #2
Math Team

Joined: May 2013
From: The Astral plane

Posts: 2,258
Thanks: 929

Math Focus: Wibbly wobbly timey-wimey stuff.
Quote:
 Originally Posted by Jayant98 >A uniform beam of positively charged particles is moving with a constant velocity parallel to another beam of negatively charged particles moving with the same velocity but in opposite direction separated by a distance d. Then, how should be the variation of magnetic field B along a perpendicular line drawn between the two beams?(For better view, imagine positive beam to be x-axis and negative beam to be y=1 line.) I know that there will be electric field and hence the magnetic field. But I don't know how to proceed for the relation
This is an application of Ampere's Law. The magnetic field varies radially from each current and you can simply add them.

-Dan

 February 17th, 2019, 07:46 AM #3 Newbie   Joined: Feb 2019 From: United states Posts: 9 Thanks: 0 But it is charge beam and not a current carrying wire or something. Last edited by Jayant98; February 17th, 2019 at 07:53 AM.
February 17th, 2019, 07:54 AM   #4
Newbie

Joined: Feb 2019
From: United states

Posts: 9
Thanks: 0

Quote:
 Originally Posted by topsquark This is an application of Ampere's Law. The magnetic field varies radially from each current and you can simply add them. -Dan
But it's not a current carrying wire. Are both the charge beams same as the current carrying wire?

Last edited by skipjack; February 17th, 2019 at 09:06 AM.

February 17th, 2019, 08:33 AM   #5
Senior Member

Joined: Nov 2015
From: United States of America

Posts: 198
Thanks: 25

Math Focus: Calculus and Physics
Quote:
 Originally Posted by Jayant98 But it is charge beam and not a current carrying wire or something.
Current is defined as:

$I = \frac{dq}{dt}$

When we think about current, typically we think about negatively charge particles (electrons) crossing a perpendicular plane in the wire every time interval dt. If we had positively charged particles (like we do in this problem) moving the same effect would be happening, just the magnetic field direction would be flipped. Use the right hand rule and Amperes law:

$$\oint B\cdot\,ds = ยต_oI_o$$

To investigate this further.

February 17th, 2019, 09:11 AM   #6
Math Team

Joined: May 2013
From: The Astral plane

Posts: 2,258
Thanks: 929

Math Focus: Wibbly wobbly timey-wimey stuff.
Quote:
 Originally Posted by Jayant98 But it's not a current carrying wire. Are both the charge beams same as the current carrying wire?
A current is defined as a moving set of charges. No one says they have to be constricted to a wire. For example, we can also have charges moving along a surface.

-Dan

 Tags beams, field, magnetic, varies

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post Marva Physics 1 February 11th, 2018 06:44 PM Raphael Physics 0 May 1st, 2012 12:23 PM FishFace Physics 3 October 27th, 2011 06:39 AM r-soy Physics 1 February 18th, 2011 11:59 AM r-soy Physics 3 February 6th, 2011 10:15 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top