Charged particles in magnetic field

Click For Summary
SUMMARY

The discussion focuses on calculating the charge-to-mass ratio (q/m) of a newly discovered particle that passes undeflected through crossed electric and magnetic fields. Given the electric field strength (E) of 316 V/m and magnetic field strength (B) of 0.00127 T, the velocity (v) of the particles is determined to be 248818.8976 m/s using the formula v=E/B. The charge-to-mass ratio is calculated as m/q=0.01119723 C/kg by substituting the radius (r=2.97 cm) and magnetic field strength into the derived equations.

PREREQUISITES
  • Understanding of electromagnetic theory, specifically the behavior of charged particles in electric and magnetic fields.
  • Familiarity with formulas such as v=E/B and m/q=(rB')/v.
  • Knowledge of unit conversions, particularly between centimeters and meters.
  • Basic algebra skills for manipulating equations and solving for variables.
NEXT STEPS
  • Explore the derivation of the Lorentz force equation and its applications in particle physics.
  • Learn about the principles of cyclotron motion and its relevance in magnetic confinement.
  • Investigate methods for measuring charge-to-mass ratios in experimental physics.
  • Study the implications of electric and magnetic field interactions on particle trajectories.
USEFUL FOR

Physicists, students studying electromagnetism, and researchers involved in particle physics or accelerator technology will benefit from this discussion.

Aerospace
Messages
39
Reaction score
0
I've been trying to work this, but the way I'm substituting, I get no variables left...:-\ It's...freaky lol.
The question is
Suppose a new particle is discovered, and it is found that a beam of these particles passes undeflected through "crossed" electric and magnetic fields, where E=316 V/m and B=0.00127 T. If the eleectric field is turned off, the particles moe in the magnetic field in circular paths of radius r=2.97 cm. Determine q/m for the particles from these data. Answer in units of C/kg.

The way I worked this is I used the foruma v=E/B to find the velocity which vame out to be 248818.8976 m/s then I plugged the v into the equation m/q=(rB')/v and since we don't know v or q those remain as variables. Then I plug the values into Em = rB'Bq and so of course, no variables left.

*sighs* help anyone?
 
Physics news on Phys.org
Neverrrrminnddddd lol

I used the v value that I got, and plugged it into r=(mv)/(qB)

:-D thanks ya'll
do help with my other post? lol
 


It seems like you are on the right track with your approach. Let's break down the steps and see if we can find where the issue might be.

First, we are given the electric field strength (E) and magnetic field strength (B) as well as the radius (r) at which the particles move in a circular path when only the magnetic field is present.

Using the formula v=E/B, we can find the velocity of the particles to be 248818.8976 m/s.

Next, we can use the formula m/q=(rB')/v, where B' is the magnetic field strength in the absence of the electric field. Since the particles are moving in a circular path, we can use the formula B'=Bqv/m to find B'.

Substituting B'=Bqv/m into the previous equation, we get m/q=(rBqv)/v. We can simplify this to m/q=rBq.

Now, we can use the given information of the radius (r) and the magnetic field strength (B) to find Bq. Substituting these values, we get Bq=0.00127*2.97=0.0037659.

Finally, we can substitute this value into the equation m/q=rBq to get m/q=2.97*0.0037659=0.01119723.

So, the value of m/q for the particles is 0.01119723 C/kg.

I hope this helps and clarifies the steps for solving this problem. Remember to always check your units and make sure they cancel out correctly. Good luck!
 

Similar threads

Replies
1
Views
2K
  • · Replies 3 ·
Replies
3
Views
1K
Replies
14
Views
3K
Replies
12
Views
2K
  • · Replies 2 ·
Replies
2
Views
833
  • · Replies 25 ·
Replies
25
Views
2K
Replies
3
Views
2K
Replies
1
Views
2K
Replies
3
Views
2K
  • · Replies 8 ·
Replies
8
Views
2K