Induced current due to rotating coil

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SUMMARY

The discussion focuses on calculating induced current in a rotating coil using the equation Emf = NBA*ωsin(ωt). The user initially struggles with the absence of resistance (R) and surface charge density (ρ) values. It is concluded that the resistivity of copper, particularly for 22 gauge wire, is essential for determining resistance, which can be found in standard tables. Educators typically provide necessary resistivity data during exams, making it uncommon for students to memorize these values.

PREREQUISITES
  • Understanding of electromagnetic induction principles
  • Familiarity with the equation Emf = NBA*ωsin(ωt)
  • Knowledge of resistivity and resistance calculations
  • Basic concepts of wire gauge and its implications on resistance
NEXT STEPS
  • Research the resistivity values for different materials, focusing on copper
  • Study the relationship between wire gauge and resistance per unit length
  • Learn how to apply the equation Emf = NBA*ωsin(ωt) in practical scenarios
  • Explore resources on electromagnetic induction and induced current calculations
USEFUL FOR

Students preparing for physics exams, educators teaching electromagnetic concepts, and anyone interested in understanding induced current in rotating systems.

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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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.
 

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