Calculating Induced Voltage in a Rotating Rectangular Loop with Magnetic Field

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Discussion Overview

The discussion revolves around calculating the induced voltage in a rotating rectangular loop placed in a magnetic field. Participants explore the application of Faraday's law of induction and the implications of the magnetic field's direction relative to the loop's rotation.

Discussion Character

  • Technical explanation
  • Mathematical reasoning
  • Debate/contested

Main Points Raised

  • Some participants propose using the integral form of the induced voltage, V(induced) = ∫(u X B).dS, while expressing uncertainty about the magnetic field's direction.
  • One participant clarifies that if the loop's axis of rotation is in the x direction, the magnetic field could be oriented in the y or z direction.
  • Another participant suggests that applying Faraday's law of induction might simplify the calculation, equating emf to the rate of change of magnetic flux.
  • There is a question about how to apply Faraday's law given that the conductor's position is changing, with concerns that it may lead back to the original equation used.
  • Some participants note that the changing position of the conductor is what causes the magnetic flux to change, indicating a relationship between the magnetic field and the area vector.
  • One participant mentions that using the equation for magnetic flux (B x A) might be a more straightforward approach.

Areas of Agreement / Disagreement

Participants express differing views on the best approach to calculate the induced voltage, with some favoring the integral method and others advocating for Faraday's law. The discussion remains unresolved regarding the optimal method to apply in this scenario.

Contextual Notes

There are limitations in the discussion regarding the assumptions about the magnetic field's direction and the implications of the loop's changing position on the induced voltage calculation.

lazyaditya
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Q. A 30 cm by 40 cm rectangular loop rotates at 130 rad/sec in a magnetic field 0.06Wb/metre sqre normal to the axis of rotation. If the loop has 50 turns, determine the induced voltage in the loop ?

Attempt !

V(induced) in 1 turn = ∫(u X B).dS

my vector u will be ρω in a∅ direction but i am unable to understand the direction of magnetic field what does it mean by direction perpendicular to axis of rotation ?
 
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lazyaditya said:
Q. A 30 cm by 40 cm rectangular loop rotates at 130 rad/sec in a magnetic field 0.06Wb/metre sqre normal to the axis of rotation. If the loop has 50 turns, determine the induced voltage in the loop ?

Attempt !

V(induced) in 1 turn = ∫(u X B).dS

my vector u will be ρω in a∅ direction but i am unable to understand the direction of magnetic field what does it mean by direction perpendicular to axis of rotation ?

It means that the magnetic field goes straight through the loop. Say that the loop's axis of rotation is the x direction, then the magnetic field could be in the y or z direction.
 
lazyaditya said:
Q. A 30 cm by 40 cm rectangular loop rotates at 130 rad/sec in a magnetic field 0.06Wb/metre sqre normal to the axis of rotation. If the loop has 50 turns, determine the induced voltage in the loop ?

Attempt !

V(induced) in 1 turn = ∫(u X B).dS

my vector u will be ρω in a∅ direction but i am unable to understand the direction of magnetic field what does it mean by direction perpendicular to axis of rotation ?

I think it would be easier to use Farady's law of induction which equates emf to rate of change of magnetic flux.
 
berkeman said:
It means that the magnetic field goes straight through the loop. Say that the loop's axis of rotation is the x direction, then the magnetic field could be in the y or z direction.

but then if i am considering the direction of rotation to be A∅ wouldn't both the directions Aρ
and Az will be perpendicular to it !
 
rude man said:
I think it would be easier to use Farady's law of induction which equates emf to rate of change of magnetic flux.
how should i use faraday law in this the conductor position is changing ! wouldn't the faraday law equation result in the equation i have used in the end !
 
lazyaditya said:
how should i use faraday law in this the conductor position is changing ! wouldn't the faraday law equation result in the equation i have used in the end !

Yes, the conductor position is changing. That's what makes the magnetic flux change, since flux = B dot area where B and area are vectors ...

Yes, yopur equation is tantamount to farady's law. i just meant that using flux = B x A is easier ...
 

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