PhysicsBowl 2019 Q41

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PhysicsBowl 2019

41) For this question, we are asked to find the induced electromotive force produced by the magnetic field. We can do this by using Faraday's law of induction for induced voltage.

Where E is electromotive force, N is number of coils, Φ is flux, t is time, B is magnetic field, A is area, and θ is angle between normal of plane and field.

Note that the negative is not including in the magnitude, but is there to signify that the induced electromotive force will create a current in the opposite direction of the effect the creates it.

It is important to realize that θ is the angle between the normal to the plane and the magnetic field. So by drawing this out and by drawing the angle given to us, we can find θ.

Where θ is angle between normal of plane and magnetic field

Finally, by converting units and plugging in values, we can use Faraday's law to find the induced voltage.

Where E is electromotive force, N is number of coils, Φ is flux, t is time, B is magnetic field, A is area, and θ is angle between normal of plane and field.

Answer: D