Current through a coil in a magnetic field

EMF = (0.0028\;m^2 * ((0.42-0.02)/3)) * 90\;turns = 0.00336\;V \\I = EMF/Resistance = 0.00336\;V/6\;\Omega = 0.00056\;A = 0.56\;mA \\In summary, the average current in the wire is 0.56 mA, not 0.56 A. The error in the attempted solution is due to using the area in cm² instead of m².
  • #1
cheeseboy
1
0
Question:

A coil of 90 turns, of resistance 6 ohm and area 28 cm² moves from a
uniform magnetic field of 0.02 Tesla to one of 0.42 Tesla in 3.0 second.
What average current flows in the wire (in amp) ?

Relevant equations:

EMF= (Area * Rate of change of magnetic flux) * Number of turns

I = EMF/Resistance

Attempted Solution:

EMF= ((0.28^2) * ((0.42-0.02)/3)) * 90 turns = 3.36

I = EMF/Resistance = 3.36/6 = 0.56 amps (i believe this is correct)

however answer given is 0.0056 amps where am I missing this factor of 100?
 
Last edited:
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  • #2
cheeseboy said:
Question:

A coil of 90 turns, of resistance 6 ohm and area 28 cm² moves from a
uniform magnetic field of 0.02 Tesla to one of 0.42 Tesla in 3.0 second.
What average current flows in the wire (in amp) ?

Relevant equations:

EMF= (Area * Rate of change of magnetic flux) * Number of turns

I = EMF/Resistance

Attempted Solution:

EMF= ((0.28^2) * ((0.42-0.02)/3)) * 90 turns = 3.36

I = EMF/Resistance = 3.36/6 = 0.56 amps (i believe this is correct)

however answer given is 0.0056 amps where am I missing this factor of 100?
[tex]28\;cm^2 \neq 0.28\;m^2[/tex]
 

What is the definition of current through a coil in a magnetic field?

The current through a coil in a magnetic field refers to the flow of electric charge through a coil of wire that is placed in a magnetic field. This current can be induced by either moving the coil within the magnetic field or by changing the magnetic field itself.

How is current through a coil in a magnetic field calculated?

The current through a coil in a magnetic field can be calculated using Ohm's law, which states that current (I) is equal to the voltage (V) divided by the resistance (R). In this case, the resistance is the total resistance of the coil, which includes the resistance of the wire and any other components in the circuit.

What is the relationship between current and magnetic field strength in a coil?

The relationship between current and magnetic field strength in a coil is directly proportional. This means that as the strength of the magnetic field increases, the current through the coil also increases. Similarly, if the magnetic field strength decreases, the current will also decrease.

Can the direction of current through a coil in a magnetic field be reversed?

Yes, the direction of current through a coil in a magnetic field can be reversed by changing the direction of the magnetic field or by changing the direction of the coil. This is known as Faraday's law of induction, which states that a change in magnetic field will induce an electric current in a conductor.

What are some practical applications of current through a coil in a magnetic field?

Current through a coil in a magnetic field has various practical applications, such as in electric motors, generators, and transformers. It is also used in devices like speakers and microphones, which convert electrical energy into sound and vice versa.

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