How does a current balance work?

Click For Summary
A current balance measures the force exerted on a current-carrying wire in a magnetic field and is used to determine the mass needed for balance. To solve the practice problem, the equation F = BIL can be used, where B is the magnetic field strength in Teslas, I is the current in Amperes, and L is the length of the wire. The length of the wire is crucial for calculating the force, and without it, assumptions must be made, such as setting L to 1 meter for simplification. The weight of the mass (mg) must equal the magnetic force for the system to balance. Understanding units is essential for accurate calculations in physics problems.
Tangeton
Messages
62
Reaction score
0
< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color]

I am looking for a very simplistic and understandable explanation for how it works as I don't seem to find any place that explains it well... I am just doing A Level which is equivalent to high school.

Also I've looked at a practice question in the book, and I've been given B (2.0x10^-3) and current (1.0A). I've been asked to find what the mass must be hanged on the other side in order for the system to be balanced, but I don't know how to since I haven't been given the length of the wire... I wanted to equate F = BIL (if I had the length) to the weight of the mass (mg) but I cannot do that unless I assume some sort of length. When I said l = 1 then I got 2.0 x 10^-4. There is no answer in the book... any ideas of how I'd approach this?
 
Last edited by a moderator:
Physics news on Phys.org
Tangeton said:
< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >

I am looking for a very simplistic and understandable explanation for how it works as I don't seem to find any place that explains it well... I am just doing A Level which is equivalent to high school.

Also I've looked at a practice question in the book, and I've been given B (2.0x10^-3) and current (1.0A). I've been asked to find what the mass must be hanged on the other side in order for the system to be balanced, but I don't know how to since I haven't been given the length of the wire... I wanted to equate F = BIL (if I had the length) to the weight of the mass (mg) but I cannot do that unless I assume some sort of length. When I said l = 1 then I got 2.0 x 10^-4. There is no answer in the book... any ideas of how I'd approach this?

What's a current balance? Can you post a diagram or picture?

Also, it's best if you make a habit of carrying units along in your variables and calculations. When you say you are given "given B (2.0x10^-3)", what are the units?
 
berkeman said:
What's a current balance? Can you post a diagram or picture?

Also, it's best if you make a habit of carrying units along in your variables and calculations. When you say you are given "given B (2.0x10^-3)", what are the units?

Unit is the Tesla.
2q1ywqb.jpg
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

Similar threads

  • · Replies 2 ·
Replies
2
Views
6K
Replies
21
Views
3K
  • · Replies 2 ·
Replies
2
Views
2K
Replies
2
Views
2K
  • · Replies 2 ·
Replies
2
Views
3K
  • · Replies 13 ·
Replies
13
Views
4K
Replies
17
Views
2K
  • · Replies 39 ·
2
Replies
39
Views
19K
Replies
4
Views
1K
  • · Replies 7 ·
Replies
7
Views
2K