Falling Loop in Magnetic Field: How long to leave field?

Thank you for your help. In summary, the conversation discusses a 0.2m x 0.2m metal loop with a mass of 10g and resistance of 0.010Ω in a horizontal magnetic field of 1.0 T. The loop is oriented vertically and is released from rest, falling through the magnetic field. The conversation focuses on finding the terminal velocity of the loop and the time it takes for the loop to leave the field. The concept of induction is mentioned as a key to solving the problem.
  • #1
dekoi
Question:

0.2m x 0.2m metal loop is oriented vertically.
mass = 10g
resistance = 0.010Ω
magnetic field = 1.0 T

The magnetic field is horizontal (into the page), perpendicular to the loop, and fills the top half of the loop. There is no magnetic field in the bottom half of the loop.
The loop is released from rest and allowed to fall.

a)
Show that the loop reaches a terminal velocity, and find a value for it.
b) How long will it take the loop to leave the field? Assume the time needed to reach the terminal velocity is negligible. How does this compare to the time it would take the loop to fall the same distance in the absence of a field?


My Answer:
a) I am uncertain of whether there is a force exerted on the loop by the magnetic field. I would assume that the force acts in the horizontal direction, which would not affect the vertical motion of the loop. However, as the loop falls, it is no longer perpendicular to the magnetic field, and therefore creates an angle which will in turn create a force... ?
So if there is a force, then the equation is F = ILBsinΦ. However, I do not have a value for current, and I do not see a way of finding it.

b) I have not attempted part b) yet, since I have not even finished a). However, if you have any hints, please provide me with them.

Thank you.
 
Last edited by a moderator:
Physics news on Phys.org
  • #2
dekoi said:
Question:

0.2m x 0.2m metal loop is oriented vertically.
mass = 10g
resistance = 0.010Ω
magnetic field = 1.0 T

The magnetic field is horizontal (into the page), perpendicular to the loop, and fills the top half of the loop. There is no magnetic field in the bottom half of the loop.
The loop is released from rest and allowed to fall.

a)
Show that the loop reaches a terminal velocity, and find a value for it.
b) How long will it take the loop to leave the field? Assume the time needed to reach the terminal velocity is negligible. How does this compare to the time it would take the loop to fall the same distance in the absence of a field?


My Answer:
a) I am uncertain of whether there is a force exerted on the loop by the magnetic field. I would assume that the force acts in the horizontal direction, which would not affect the vertical motion of the loop.
Why do you say the force would be horizontal ? How do you calculate what the force will be (magnitude and direction) ?
 
  • #3
Gokul:
If there is a force, then the equation is F = ILBsinΦ. However, I do not have a value for current, and I do not see a way of finding it.
 
  • #4
Look at your thread title again. Do you know what that term means ? If not, ask Faraday !
 
  • #5
Gokul,
You are only confusing me, and are not helping me in any way to answer the problem.

Does anyone else have any advice?
 
  • #6
The key to solving this was mentioned in the thread title, induction. Gokul pointed it out so he was helping you. As the magnetic flux through the loop changes what happens?
 
  • #7
It's okay... I've figured it out.
 

What is electromagnetic induction?

Electromagnetic induction is a phenomenon where a changing magnetic field can induce an electric current in a conductor or circuit.

How does electromagnetic induction work?

According to Faraday's law, when there is a change in magnetic flux through a conductor, an electromotive force (EMF) is induced in the conductor, causing an electric current to flow.

What are the applications of electromagnetic induction?

Electromagnetic induction is used in various devices and technologies, such as generators, transformers, motors, and wireless charging. It is also the basis for many technologies, including electric power distribution and wireless communication.

What factors affect the strength of electromagnetic induction?

The strength of electromagnetic induction is influenced by the rate of change of the magnetic field, the number of turns in the conductor, and the permeability and resistance of the conductor.

What is the difference between electromagnetic induction and electromagnetic radiation?

Electromagnetic induction involves the generation of an electric current through a changing magnetic field, while electromagnetic radiation refers to the emission of electromagnetic waves, such as light, radio waves, and X-rays.

Similar threads

  • Introductory Physics Homework Help
Replies
2
Views
210
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
8
Views
356
  • Introductory Physics Homework Help
Replies
4
Views
269
  • Introductory Physics Homework Help
Replies
2
Views
56
  • Advanced Physics Homework Help
Replies
16
Views
3K
Replies
8
Views
410
  • Introductory Physics Homework Help
2
Replies
37
Views
2K
  • Advanced Physics Homework Help
Replies
6
Views
2K
  • Electromagnetism
Replies
32
Views
2K
Back
Top