Induced EMF, finding current

The emf is then N times that, and you need to divide by R to get the current.In summary, a coil with 253 turns of wire, a total resistance of 28 Ohms, and a cross-section area of 0.36m^2 is positioned in a plane perpendicular to a powerful electromagnet. By using the equation E = BA/t, the average current induced in the coil during the 0.33s that the magnetic field drops from 2.2T to 0.0T can be calculated. However, since the emf is induced in each coil of wire, the total flux linkage must be multiplied by the number of turns, resulting in an average current of 0.085714285
  • #1
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Homework Statement



A coil with 253 turns of wire, a total resistance of 28 Ohms, and a cross-section area of 0.36m^2 is positioned in a plane perpendicular to the field of a powerful electromagnet.
What average current is induced in the coil during the 0.33s that the magnetic field drops from 2.2T to 0.0T? Answer in units of A.


Homework Equations



E = BA / t
V = IR

The Attempt at a Solution



EMF = Change in B * Area / time
= (2.2 * .36) / .33

I plug that into V = IR

V = IR
[(2.2 * .36) / .33] = I * 28 Ohms
I = [(2.2 * .36) / .33] / 28 = 0.0857142857A

However I get the wrong answer.
I think it has something to do with the 253 coils of wire but I'm not sure.
Any help is appreciated.
 
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  • #2
Yes, the emf you calculate is induced in each coil of wire, so the total flux linkage at the start is BAN where N is the nuber of turns.
 

1. What is induced EMF?

Induced EMF, or electromotive force, is the voltage generated in a conductor when it is exposed to a changing magnetic field.

2. How is induced EMF calculated?

Induced EMF can be calculated using Faraday's Law, which states that the magnitude of the induced EMF is equal to the rate of change of the magnetic flux through the conductor.

3. What factors affect the magnitude of induced EMF?

The magnitude of induced EMF is affected by the strength of the magnetic field, the speed at which the magnetic field changes, and the length of the conductor.

4. How is induced EMF related to current?

According to Ohm's Law, the induced EMF will cause a current to flow through the conductor, as long as there is a complete circuit. The magnitude of the current is determined by the resistance of the circuit.

5. What are some real-world applications of induced EMF?

Induced EMF is the principle behind generators and transformers, which are used to produce and distribute electricity. It is also used in devices such as electric motors and induction cooktops.

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