uniform magnetic field is one in which the magnetic field is the same at all points in space, both in module and in direction and direction. In it the induction lines are parallel and are equally spaced from one another. It can be obtained inside a solemnOgo long enough.
Read too: Electromagnetism — the part of physics that relates electricity and magnetism
Magnetic Field Induction Lines
Induction lines are a feature that allows you to more easily visualize the spatial configuration of the magnetic field. Such lines have some characteristicsimportant, to know:
- are always closed;
- exit through magnetic north and enter magnetic south;
- when equally spaced, they represent a uniform magnetic field;
- they are quite concentrated in the vicinity of the magnetic poles, as the magnetic field is more intense in these places.
Unlike electric field force lines, the magnetic field lines are always closed. This is because it is not possible that they existmonopolesmagnetic, that is, any magnetized body has both a south pole and a north magnetic pole.
Definition of uniform magnetic field
The definition of a uniform magnetic field is simple: it is a field that presents the same module, direction and sense at all points of space. Graphically, the uniform magnetic field is represented by a region where the lines of induction are parallel and are equally spaced from each other.
It is possible to produce a uniform magnetic field by means of a long enough solenoid. In this case, the electric current running along the solenoid wires produces a magnetic field very similar to a uniform magnetic field in the center of the solenoid. As we approach the ends of the solenoid, however, edge effects cause the magnetic field to become more heterogeneous.
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The following figure shows a long solenoid. Inside, you can see that themagnetic field lines areparallel and evenlyspaced. Such conditions indicate that, in these regions, the magnetic field is considered uniform.
Relationship between uniform magnetic field and magnetic force
Uniform magnetic fields are important for the study of magnetic phenomena, since, through them, it is possible that calculations involving the interaction between magnetic fields and electrical charges in motion become simpler to resolve.
When a charged particle interacts with a magnetic field, a magnetic force acts on that particle. THE strengthmagnetic is perpendicular to the magnetic field vector, as well as to the particle's own velocity direction, thus, these particles start to describe circular or even helical paths while they are moving in a region of uniform magnetic field.
The most common calculations involving uniform magnetic fields are those where we must determine the magnetic force exerted on moving loads. The magnetic force can be calculated by productin betweenOmodulegiveschargeelectric, The velocitygivesparticle it's the moduleoffieldmagnetic, in addition to the sine of the angle that is formed between v and B. Check out the formula below:
F – magnetic force (N)
what – electric charge (C)
v – particle velocity (m/s)
B – magnetic field (T)
θ – angle between v and B
See too: Electromagnetic Induction — What Is It And How Does It Work?
Exercises on Uniform Magnetic Field
Question 1 — Regarding the lines of induction of a uniform magnetic field, the following statements are made.
I – They are closed lines.
II – These are lines that leave magnetic south and enter magnetic north.
III – They are equally spaced lines.
IV – They are open lines that leave the positive charges and enter the negative charges.
They are correct:
a) I, II and II.
b) I and II.
c) II and III.
d) III and IV.
Resolution:
Let's analyze the statements:
I - TRUE.
II - TRUE.
III - TRUE.
IV - FALSE. The lines that exit the positive charges and enter the negative charges are the electric field lines.
Question 2 — The uniform magnetic field is characterized by uniform separation of the induction lines. Check the alternative that does not represent a uniform magnetic field characteristic.
a) The lines of the uniform magnetic field are parallel.
b) Uniform magnetic field can be obtained inside a sufficiently long solenoid.
c) In a uniform magnetic field, the magnitude, direction and direction of the magnetic field are the same at all points.
d) In a uniform magnetic field, field lines may cross.
Resolution:
The false alternative is the letter D, since the lines of induction of the magnetic field, uniform or not, do not cross.
question 3 – An electrically charged particle with an electrical charge of 5 µC enters a region of uniform magnetic field of intensity equal to 2.0.10-5 T, at a speed of 300 m/s, perpendicular to the magnetic field. Determine the strength of the magnetic force acting on the particle.
a) 3.0.10-8 N
b) 2.0.10-7 N
c) 4.0.10-9 N
d) 5.0.10-6 N
Resolution:
To respond to the exercise, we will calculate the magnetic force. Watch:
By Rafael Hellerbrock
Physics teacher
Would you like to reference this text in a school or academic work? Look:
HELERBROCK, Rafael. "Uniform magnetic field"; Brazil School. Available in: https://brasilescola.uol.com.br/fisica/campo-magnetico-uniforme.htm. Accessed on July 27, 2021.
