Induced current due to rotating coil

In summary, the student is seeking help on finding induced current in a practice exam problem. They mention using equations for EMF and surface charge density, but do not have the necessary information for resistance. They suggest there may be a table of resistivity for copper, which would make finding resistance easier.
  • #1
caljuice
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I attached a problem from a practice exam. I'm stuck on part b). Part A, I'm assuming the answer is the standard equation for an infinite current sheet.

How do I find induced current? I can only think of using Emf = NBA*ωsintωt
Where Emf= I/R, but I don't have resistance.

Only other equation I know is K= ρ*ω*r , where ρ is surface charge density, but don't got that either.

Any help on the first step?

EDIT: Thinking now there might have been a table of resistivity for the copper. Then R can be found easily.
 

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  • #2
caljuice said:
I attached a problem from a practice exam. I'm stuck on part b). Part A, I'm assuming the answer is the standard equation for an infinite current sheet.

How do I find induced current? I can only think of using Emf = NBA*ωsintωt
Where Emf= I/R, but I don't have resistance.

Only other equation I know is K= ρ*ω*r , where ρ is surface charge density, but don't got that either.

Any help on the first step?

EDIT: Thinking now there might have been a table of resistivity for the copper. Then R can be found easily.
Yes, you need the resistivity of copper and the fact that it is 22 gauge wire. On an actual exam, most teachers or professors would supply you with the necessary information to figure out R; it would be very unusual to require students to memorize the resistivity of different materials or the diameters of different wire gauges.

Alternatively, the information could be given as a table of resistance/length (Ω/m) for various gauges of copper wire.
 

Related to Induced current due to rotating coil

What is induced current due to rotating coil?

Induced current due to rotating coil refers to the production of an electric current in a conductor that is caused by a changing magnetic field. This phenomenon is known as electromagnetic induction and was first discovered by Michael Faraday in the early 19th century.

How is induced current produced in a rotating coil?

Induced current is produced in a rotating coil through the movement of the coil within a magnetic field. As the coil rotates, the magnetic field lines passing through it change, which creates a voltage difference and generates an electric current in the coil.

What factors affect the magnitude of induced current in a rotating coil?

The magnitude of induced current in a rotating coil is affected by several factors, including the strength of the magnetic field, the speed of rotation, the number of turns in the coil, and the angle between the coil and the magnetic field lines.

How is induced current used in practical applications?

Induced current in rotating coils has many practical applications, such as in generators, electric motors, and transformers. It is also used in devices such as induction cooktops and wireless chargers.

What are the advantages of using induced current in rotating coils?

The use of induced current in rotating coils allows for the conversion of mechanical energy into electrical energy, making it a highly efficient means of generating electricity. It also eliminates the need for a direct physical connection between the power source and the device, making it safer and more convenient to use.

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