Basic Coil Turn question please see

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The discussion revolves around a physics problem involving a 200-turn coil made of copper wire, where the goal is to determine the rate at which the magnetic field (B) should increase to induce a 2.0 A current. Participants express confusion regarding the problem's parameters, particularly the lack of information about the coil's radius or cross-sectional area, which are crucial for calculating induced electromotive force (emf). There is also ambiguity in the interpretation of the phrase "Magnetic field is perpendicular to coil," leading to further uncertainty about the setup. Additionally, a separate inquiry about an electrical appliance's power factor and supply voltage at a different frequency is introduced, indicating a broader interest in electrical concepts. Overall, the thread highlights the challenges of solving physics problems with incomplete information.
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Homework Statement


200-turn,coil of 8.0cm length is made of 0.50mm-diameter copper wire.
Magnetic field is perpendicular to coil. At what rate B should increase to induce a 2.0 A current in the coil?

Homework Equations





The Attempt at a Solution


i am not getting anthing
 
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helpphysics said:
i am not getting anthing

Hello helpphysics,

Why don't start by stating any relevant equations, and then describe where and how you are getting stuck (showing your work as you go).
 
i am sorry i am not getting it
i just know that emf = A*∂B/∂t & thus
2R = A*∂B/∂t
 
Hello helpphysics,

I've been thinking about this problem a lot, and a couple of things are troubling me.

Is this a homework problem?

Is there anything missing in the problem statement, such as the radius, diameter, or cross sectional area of the coil? I see that the length is given. The length is useful if the coil is producing a magnetic field, but typically when discussing induced emf, something relating to the cross sectional area is given.

Are there any other coils or solenoids involved in this problem?

The problem statement says, "Magnetic field is perpendicular to coil." Initially I took this to mean that the cross sectional plane of the coil was perpendicular to the magnetic field (meaning the normal vector of the cross sectional area is parallel to the field). But thinking about it more, I think most people might interpret the problem statement as saying the major axis of the coil is perpendicular to the magnetic field. But if that was the case, there would be no induced emf at all! All I'm saying is that "Magnetic field is perpendicular to coil" is kind of a weird way to state the problem.

The more I look at this problem, the more it seems that maybe something is missing. :confused:
 
Last edited:
Sorry mate. No more info has been given.
Don't worry you are not the only one going nuts over this. Physics is a hard nut! :-p
 
Anyway can you please help me out with the following?

240V , 50 Hz electrical appliance is rated at 2 kW. It has a lagging power factor of 0.7
(a) What is appliances power factor when it is used on a 60Hz supply.
(b) What is supply voltage required to maintain appliance at its rated power when operated off a 60 Hz supply?

Please look into this.
Thanks
 
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