Respuesta :
A) An equation for the magnetic flux through the small coil at an instant of time when the area vector is at some angle to the magnetic field is;
Φ = BA cos θ
B) An expression that shows how the magnetic flux through the small coil changes as it turns with a constant angular speed is;
dΦ/dt = -BAω sinθ
I have attached an image showing a vector giving the direction of the magnetic field, the area vector and the angle between the magnetic field and the area vector.
A) The general formula for Magnetic flux is;
Φ = BA cos θ
Where;
B is magnetic field
A is area
θ is angle between magnetic field and the normal to the area
B) We are told that the magnetic flux changes as it turns with a constant angular speed.
Thus, we will differentiate both sides with respect to t.
dΦ/dt = -BA sinθ (dθ/dt)
Where (dθ/dt) is angular speed written as ω
Thus, we now have;
dΦ/dt = -BAω sinθ
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