Physics magnetic flux problem. Please Help!!! Will award best answer!!?

A magnetic field has a magnitude of B=.95T. It is directed perpendicular to a circular loop of wire that has a radius of .15m. The loop of wire rotated 90 degrees so that the magnetic field is parallel to the loop. What is the change in magnetic flux through the loop?

3 Answers

  • Vaman
    Lv 7
    3 years ago

    0. lux = field strength* area. The area exposed to the field strength is 0. Therefore, the magnetic field strength is 0.

  • 3 years ago

    Wouldn't the change in magnetic flux be 0.95T? The coil was orthogonal to the direction of the flux and now it's parallel. There is no magnetic flux _through_ the loop

  • Anonymous
    3 years ago

    phi = int_0^(2πθ) int_0^(0.15) 0.95*r dr dθ = 0.021375πθ;

    dphi/dt = dphi/dθ * dθ/dt = emf = 0.021375πθ;

    dphi/dt = 0.021375π*(dθ/dt) is the final answer because we do not know what the rate of the change of the loop was but that it was

    rotating angular.

    If you use phi = N*B*A*cos(theta);

    dphi/dt = N*B*A*(-sin(θ))*(dθ/dt) = (1)*(0.95)*((0.15)^2)*π*(-sin(90 degrees))*(dθ/dt) = -0.021375π*(dθ/dt)

    My guess is the answer is zero because θ = π/2; dθ/dt = 0;

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