contestada

A flat loop of wire consisting of a single turn of cross-sectional area 8.60 cm2 is perpendicular to a magnetic field that increases uniformly in magnitude from 0.500 T to 2.40 T in 1.02 s. What is the resulting induced current if the loop has a resistance of 2.80

Respuesta :

Answer:

The  induced current is [tex]I = 5.72*10^{-4 } \ A[/tex]

Explanation:

From the question we are told that

     The cross-sectional area is  [tex]A = 8.60 \ cm^2 = \frac{8.60 }{10000} = 8.60 *10^{-4} \ m[/tex]

     The initial value of magnetic field is  [tex]B_1 = 0.500 \ T[/tex]

     The  value of magnetic field  at  time  t     is  [tex]B_f = 2.40 \ T[/tex]

     The number of turns  is  N  =  1  

     The  time taken is   [tex]dt[/tex]=  1.02 \ s  

       The resistance of the loop is  [tex]R = 2.80\ \Omega[/tex]

Generally the induced emf is mathematically represented as

         [tex]e = - \frac{d \phi}{dt }[/tex]

Where  [tex]d \phi[/tex] is the change n the magnetic flux which is mathematically represented as

          [tex]d \phi = N *A * d B[/tex]

Where [tex]dB[/tex] is the change in magnetic field which is mathematically represented as  

          [tex]d B = B_f - B_i[/tex]

substituting values  

         [tex]d B = 2.40 - 0.500[/tex]

         [tex]d B = 1.9 \ T[/tex]

So  

        [tex]d \phi = 1 * 1.9 * 8.60 *10^{-4}[/tex]

       [tex]d \phi = 1.63*10^{-3} \ T[/tex]

So  

      [tex]e = - \frac{1.63 *10^{-3}}{ 1.02 }[/tex]

      [tex]e = - 1.60*10^{-3} \ V[/tex]

     Here the negative only indicates that the emf is acting in opposite direction of the motion producing it so the magnitude of the emf is  

       [tex]e = 1.60*10^{-3} \ V[/tex]

Now the induced current is evaluated as follows

       [tex]I = \frac{e}{R }[/tex]

substituting values  

      [tex]I = \frac{1.60 *10^{-3}}{2.80 }[/tex]

      [tex]I = 5.72*10^{-4 } \ A[/tex]