Is the Emf in a Coil of 100 Turns 0 When B Field Decreases from 1.0 T?

[tandoorichicken]

Please tell me if this is right:

A coil contains 100 turns of wire in a loop 15cm in diameter. The loop is placed between the poles of a large electromagnet B= 1.0 T, with the plane of the loop perpendicular to the field. If the magnetic field is steadily reduced from 1.0 T to 0 in 16 seconds, is the emf in the coil = 0?

 

[Chen]

I can tell you that it's definitely not 0, not in the first 16 seconds that is.

$$\epsilon ' = \frac{d\phi B}{dt} = \frac{dBS}{dt}$$
S, the area, stays constant but B, the magnetic field, reduces constantly. So the magnetic flux through the coil changes and therefore there is EMF in it.

 

[M98Ranger]

Yes, the emf in the coil will be 0 when the magnetic field decreases from 1.0 T to 0 in 16 seconds. This is because the emf (electromotive force) is directly proportional to the rate of change of magnetic flux through the coil. When the magnetic field decreases, the magnetic flux through the coil also decreases, resulting in a decrease in emf. Since the decrease in magnetic field is steady and the rate of change of magnetic flux is constant, the emf will also be constant and equal to 0. This can be calculated using Faraday's law of induction, which states that the emf induced in a coil is equal to the negative of the rate of change of magnetic flux through the coil. Therefore, in this scenario, the emf in the coil will be 0.