How Do You Calculate Torque in a Current Loop with a Hanging Mass?

AI Thread Summary
To calculate the torque in a current loop with a hanging mass, the relevant equations include Torque = NIABsin(theta) and Torque = u * B. The loop carries a 2.0 A current and has 10 turns, with the area calculated as A = 0.1 * 0.05. The discussion highlights confusion regarding the angle theta when the loop is parallel to the magnetic field, suggesting that sin(theta) would be zero, complicating the torque calculation. Participants seek clarification on the correct application of the equations and the expected answer for the given parameters.
dtesselstrom
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Homework Statement


The 10-turn loop of wire shown in the figurelies in a horizontal plane, parallel to a uniform horizontal magnetic field, and carries a 2.0 A current. The loop is free to rotate about a nonmagnetic axle through the center. A 50 g mass hangs from one edge of the loop.


Homework Equations


Torque = u * B
Torque = (I*A) B


The Attempt at a Solution


Ive tried all sorts of things I konw that I is 2.0 A and A is .1 * .05 so that gives .01 * B = Torque and I've set torque equal to just the F of the weight times the radius and diameter and I've also tried doubling the F because the force down on both sides. No matter what I've tried it doesn't seem to work. Answers that I have gotten are 1.225. 2.45, 4.9, and .6125 so if you try this problem and get those they are wrong. Thanks for the help.
 

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If there are 10 turns in the loop, wouldn't you use the equation that incorporates the # of turns?

As far as I know, the 2nd equation you stated holds true for rectangular loops (I can't see your attachment so I don't really know what the problem set up is).

Additionally, if the loops is parallel to the magnetic field...what would sin(theta) be?
 
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I can't find any equations in my book for turns in the loop so if you could help me out with that Id appriciated it and I was wondering that myself as for the picture it is set up as a rectangular loop so I wasn't sure that the turns ment anything and wouldn't it make the sin of theta 90 degrees?
 
For any other loop that is not a rectangle, torque=NIABsin(theta), where N=# of turns.
 
ok got it thanks for the help.
 
dtesselstrom said:
ok got it thanks for the help.[/QUO
What is the answer for this question for the existing numbers? Can you help?
 
Did anybody come up with an answer for this question?
 
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