Electric force with a moving conductive bar in a magnetic field

In summary, when a conducting bar is moved to the right in a magnetic field going into the page, an electric field is set up in the bar. To determine the direction of this electric field, we can use the right hand rule for cross product. By using the index finger for velocity and the middle finger for the magnetic field, the thumb will point upwards, indicating that the electric field is upwards in the bar. Using the right hand palm rule may also be helpful in determining the direction of the electric field.
  • #1
slain4ever
63
0

Homework Statement


A conducting bar is moved to the right in a magnetic field going into the page, an electric field is set up in the bar. Is this electric field upwards or downwards.

The Attempt at a Solution


i think that because a current is being induced in the bar you use the right hand rule but the current goes the other way in the thumb therefore the electric field is up the bar. Is this correct?
 
Physics news on Phys.org
  • #2
slain4ever said:

Homework Statement


A conducting bar is moved to the right in a magnetic field going into the page, an electric field is set up in the bar. Is this electric field upwards or downwards.

The Attempt at a Solution


i think that because a current is being induced in the bar you use the right hand rule but the current goes the other way in the thumb therefore the electric field is up the bar. Is this correct?
The electric field is given by:

[tex]\vec{E} = \vec{v} \times \vec{B}[/tex]

So use the right hand rule for cross product (use the index finger for v and the middle finger for B and the thumb will give the direction of E).

AM
 
  • #3
is that a yes, by the way i think you misunderstood, i use the right hand palm rule, not the flemming thing.
 
  • #4
slain4ever said:
is that a yes, by the way i think you misunderstood, i use the right hand palm rule, not the flemming thing.
If you use the right hand two-finger-thumb rule to determine cross product, you will not be confused.

AM
 
  • #5


I can confirm that your understanding is correct. According to the right hand rule, when a conducting bar is moved in a magnetic field, an electric field is induced in the bar perpendicular to both the motion and the magnetic field. In this case, the direction of the induced current is opposite to the direction of motion, resulting in an electric field pointing upwards in the bar. This phenomenon is known as electromagnetic induction and is a fundamental principle in electromagnetism. It is important to note that the direction of the electric field can be reversed by changing the direction of either the motion or the magnetic field.
 

1. How does a moving conductive bar in a magnetic field experience an electric force?

When a conductive bar moves through a magnetic field, it cuts through the magnetic field lines and induces an electric current. This electric current then creates a magnetic field that interacts with the original magnetic field, resulting in a force on the bar known as the Lorentz force.

2. What factors affect the strength of the electric force on the conductive bar?

The strength of the electric force on the conductive bar depends on the speed of the bar, the strength of the magnetic field, the length of the bar, and the angle between the bar's velocity and the magnetic field lines. Additionally, the conductivity and resistance of the bar also play a role in determining the strength of the electric force.

3. How does the direction of the electric force change with the orientation of the conductive bar?

The direction of the electric force on the conductive bar is always perpendicular to both the bar's velocity and the magnetic field lines. If the bar is moving parallel to the magnetic field lines, there will be no electric force. If the bar is moving perpendicular to the field lines, the force will be at its maximum.

4. Can the electric force be used to generate electricity?

Yes, the electric force generated by a moving conductive bar in a magnetic field can be used to generate electricity. This is the principle behind electric generators, which use the motion of a conductive coil in a magnetic field to produce an electric current.

5. What is the relationship between the electric force and the magnetic force on a moving conductive bar?

The electric force and the magnetic force on a moving conductive bar are two components of the Lorentz force. The electric force is directly proportional to the speed of the bar and the strength of the magnetic field, while the magnetic force is proportional to the angle between the bar's velocity and the magnetic field lines. Together, these forces determine the overall motion of the conductive bar.

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
244
  • Introductory Physics Homework Help
Replies
11
Views
1K
  • Introductory Physics Homework Help
Replies
1
Views
267
  • Introductory Physics Homework Help
Replies
14
Views
1K
  • Introductory Physics Homework Help
Replies
7
Views
139
  • Introductory Physics Homework Help
Replies
8
Views
356
  • Introductory Physics Homework Help
Replies
17
Views
327
  • Introductory Physics Homework Help
Replies
11
Views
394
  • Introductory Physics Homework Help
Replies
12
Views
1K
  • Introductory Physics Homework Help
Replies
12
Views
2K
Back
Top